S



S



Sarcoidosis



Keywords


Inflammation, granulomatous disease, meningitis, cranial nerves, sensory loss


Definition and epidemiology


Sarcoidosis is a multisystem disorder of unknown etiology characterized by noncaseating granulomas. The pulmonary system is most often affected, but any organ system can be involved. Bilateral hilar adenopathy, pulmonary infiltrate, uveitis, and skin lesions are the most common presenting signs. In general, it affects young adults and is more common in African Americans. Isolated neurosarcoidosis is rare, with estimated incidence of less than 0.2 per 100,000. In 5% of patients, nervous system involvement is clinically apparent and sometimes can be the presenting sign. The most common neurologic symptoms are cranial nerve deficits (50%), headache (30%), and seizures (10%).


Clinical presentation



  1. I. Neurologic manifestations of sarcoidosis

    1. A. Cranial neuropathies. The cranial nerves themselves are most commonly involved, but they can also be compressed by meningeal involvement. The facial nerve is the most commonly affected; facial motor paresis with or without dysgeusia occurs in up to 50% of those with central nervous system (CNS) sarcoidosis. The eighth nerve is the next most commonly affected, with either auditory or vestibular symptoms, which can have sudden onset. Optic nerve is affected in approximately 15% of neurosarcoidosis cases, as optic neuropathy or papilledema. Ocular motor dysfunction is seen only occasionally, as is trigeminal sensory involvement; other cranial nerves are very rarely affected.
    2. B. Meningitis is quite common but may be clinically inapparent. Typically it is most prominent in the basal cisterns. Meningitis manifests as cranial nerve symptoms, obstructive hydrocephalus, or rarely as mass effect on the cerebral cortex when large swellings of meninges result.
    3. C. Neuroendocrine dysfunction. Granulomas in the hypothalamus or pituitary area can produce secondary hypothyroidism, hypogonadism, adrenal insufficiency, syndrome of inappropriate anti-diuretic hormone (SIADH) or diabetes insipidus, or disruption of vegetative functions such as appetite or sleep.
    4. D. Brain parenchymal lesions present either as focal cerebral dysfunction or as hydrocephalus if occluding cerebrospinal fluid (CSF) pathways, or as diffusely raised intracranial pressure if sufficiently large. These lesions may produce a diffuse cerebral vasculitis or encephalitis, manifesting as encephalopathy or seizures. They may also mimic tumors, especially meningioma, necessitating biopsy.
    5. E. Myelopathy. Extradural or intradural or extramedullary or intramedullary granuloma may cause cord compression and spinal block, or arachnoiditis.
    6. F. Neuropathies. The most common sarcoid neuropathy is chronic axonal peripheral polyneuropathy; however, neuropathies can present in multiple ways, including polyradiculopathies, individual focal mononeuropathies, or mononeuritis multiplex. They can rarely mimic Guillain-Barré syndrome.
    7. G. Myopathy, although pathologically common, is rarely clinically manifest.
    8. H. Opportunistic infection. Because treatment is immunosuppression, important parts of the differential diagnosis of CNS involvement in a patient with known systemic sarcoidosis are the various viral, fungal, and mycobacterial infections that can result from such treatment.

  2. II. Most common systemic manifestations

    1. A. Pulmonary involvement is seen at some point in 90% of patients. Any combination of parenchymal inflammation and hilar lymphadenopathy may be seen.
    2. B. Peripheral lymphadenopathy.
    3. C. Skin. Dermal or epidermal granulomas, or erythema nodosum.
    4. D. Eye. Inflammation of any portion of the orbit (conjunctivae, anterior chamber/iris, vitreous, or retina) can lead to visual impairment.

Diagnosis


Definitive diagnosis is based on biopsy demonstration of noncaseating granulomas; otherwise, the diagnosis is based on the pattern of clinical organ involvement and imaging evidence of inflammatory involvement of typical tissues. Computed tomography (CT) or preferably magnetic resonance imaging (MRI) may be helpful in localizing lesion(s) in the CNS. Spectrum of MRI findings includes nodular or diffuse leptomeningeal enhancement (40%), periventricular white matter lesion (40%), multiple intraparenchymal lesions (35%), solitary intra-axial mass (10%), and solitary extra-axial mass (5%). CSF may show high protein level (40% to 70%), lymphocytic pleocytosis (50% to 70%), and low glucose level. High immunoglobulin G (IgG) index and oligoclonal bands may be present (70%). Serum angiotensin-converting enzyme (ACE) levels may be elevated but have a sensitivity of only 56% to 86% and very low specificity; the CSF ACE level is far less sensitive but more specific if CNS structures are involved.


High erythrocyte sedimentation rate and high calcium in serum/urine may be noted. Ophthalmologic examination, conjunctival biopsy, gallium scan, chest radiograph, and bronchoscopy may help in the diagnosis of systemic sarcoidosis.


Treatment


Prednisone, 0.5 to 1 mg/kg daily, is the mainstay of treatment. In acute severe cases, 1 g/day of intravenous methylprednisolone may be administered over 3 to 5 days. If steroids are not sufficient or cannot be tapered, cyclophosphamide, azathioprine, methotrexate, or cyclosporine may be added. Most patients respond to treatment, but one-third relapse when treatment is discontinued. Long-term treatment with corticosteroids is usually required, particularly in those with involvement of basal leptomeninges or diffuse parenchymal lesions. Radiation therapy with 20 Gy should be considered in medical refractory cases.


Prognosis


Neurologic involvement in sarcoidosis is itself a poor prognostic sign. Peripheral nerve involvement and muscle involvement are often fairly benign. Cranial neuropathy and aseptic meningitis are the least poor prognostic central manifestations, with 90% of patients improving or recovering; those with symptomatic brain or spinal cord lesions, by contrast, very frequently have a progressive course.



Sciatic Nerve, Sciatica



Keywords


Sciatic nerve, sciatica, herniated disk, lumbar radiculopathy


The sciatic nerve is the largest and longest single nerve in the human body. The nerve originates at the junction of the fourth and fifth lumbar nerve roots and the first three sacral nerve roots at the lumbosacral plexus. It divides into two major branches, tibial and peroneal nerves, and innervates many muscle groups, including the hamstrings, distal adductor magnus, and all the muscles of the leg and foot. It also supplies sensation to the lateral and posterior leg and to the entire foot (Fig. 59).


Fig. 59
Figure 59 Sensory distribution of the trunk of the sciatic nerve. (From O’Brien, M. (2010). Aids to the examination of the peripheral nervous system, ed 5. Edinburgh: Saunders Elsevier).

Sciatica


The term “sciatica” can be misleading because it is not usually associated with a lesion of the sciatic nerve itself. Sciatica is pain that radiates down a lower extremity along the distribution of a lumbar or sacral nerve root. However, the term is widely used to describe a variety of pains in the back or lower limb. The most common cause of this condition is compression of a lumbar nerve root by a protruding disk (approximately 85% of cases). The most common levels are L4-L5 and L5-S1, with compression of the root below the corresponding disk. Other etiologies that have been implicated include spondylolisthesis, foraminal stenosis, synovial cysts, gluteal injection-site trauma, obstetrical sciatic damage by head of fetus or prolonged lithotomy position, and pelvic floor tumors.


Symptom distribution depends on the involved level. At L4 level, the pain is in the anterolateral thigh. At L5, the pain is typically felt in the buttock, dorsolateral thigh, lateral leg, and anterolateral foot. Compression at S1 also causes pain at the buttock, but it radiates posteriorly and reaches the fifth toe. Other symptoms are numbness, tingling, burning, and prickling sensation. Of note, aching pain in the lower back, and its increased intensity with Valsalva maneuvers, suggest disk rupture as the cause. L5 radiculopathy may cause foot drop, and S1 level lesion may cause downward tilted pelvis while walking and loss of the ankle reflex. Bilateral sciatica is usually caused by compression of cauda equina roots.


Treatment


Usually conservative. Nonsteroidal anti-inflammatory drugs (NSAIDs) or glucocorticoids may provide some relief, but the long-term effect is controversial. Opioids are not recommended as mainstay therapy. Gabapentin, pregabalin, and muscle relaxants are used but with little supporting data. A recent trial of pregabalin failed to show efficacy. Spinal manipulation may provide short-term relief if used in conjunction with exercise. Surgery may provide relief more quickly than conservative measures, but outcomes at 1 year or longer may not differ. However, acute nerve root compression with severe symptoms does warrant surgical decompression in most cases.



Sepsis



Keywords


Sepsis, neurologic complications of sepsis, sepsis-associated encephalopathy, ICU-acquired weakness


Sepsis is defined as life-threatening organ dysfunction caused by a dysregulated host response to infection. Patients with suspected infection may be screened with quick sequential (sepsis-related) organ failure assessment [quick sequential (sepsis-related) organ failure assessment (qSOFA)] (respiratory rate ≥ 22/min, change in mentation, systolic blood pressure [SBP] ≤ 100 mmHg); if this score is ≥ 2, these patients should be evaluated more thoroughly for organ dysfunction. Sepsis is confirmed if there is an acute change in total qSOFA score of 2 or more points.


Sepsis-associated encephalopathy (SAE) remains the most common neurologic complication of sepsis. SAE is thought to be secondary to a dysregulated host response to infection, as well as exposure to multiple toxins and medications. Clinical features of SAE include decreased level of alertness, confusion/disorientation, and inattention/restlessness. Exam findings are rather diffuse and may comprise asterixis, multifocal myoclonus, seizures, coarse tremor, and paratonia. The main differential diagnoses are primary neurologic conditions (i.e., central nervous system (CNS) infection, stroke/intracranial hemorrhage (ICH), nonconvulsive status epilepticus), alcohol or drug intoxication/withdrawal, Wernicke encephalopathy, serotonin, and neuroleptic malignant syndromes. The initial work-up usually includes neuroimaging, electroencephalography (EEG) and cerebrospinal fluid (CSF) analysis. Management consists of treatment of sepsis and treatment of reversible causes of encephalopathy (if present).


Intensive care unit–acquired weakness (ICUAW) (critical illness polyneuropathy and myopathy) is an important neuromuscular complication of sepsis. In this condition, neuropathy is a primary axonal degeneration, whereas myopathy is multifactorial and relates to impaired muscle structure and function. ICUAW affects both limb and respiratory muscles, and this diagnosis is suspected when there is difficulty in weaning from mechanical ventilation. The main risk factors are severity of illness, sepsis, multiple organ dysfunction, prolonged immobilization, and hyperglycemia. It is unclear whether steroids and neuromuscular blocking agents are risk factors for ICUAW. Exam findings include symmetric, distally pronounced weakness associated with atrophy, and fasciculations; deep tendon reflexes (DTRs) are typically absent or decreased. Electromyography/nerve conduction studies (EMG/NCS) may be pursued in select cases. Differentials include Guillain-Barré syndrome (GBS), metabolic derangements (i.e., hypophosphatemia), thyrotoxicosis, neuromuscular blockade, nutritional deficiency neuropathies, and paraneoplastic syndromes. Because there is no specific therapy for ICUAW, management involves avoidance of risk factors, early mobilization, and supportive care/rehabilitation. Most patients improve significantly over a period of months.



References


Schmutzhard E., Pfausler B. Neurologic complications of sepsis. Handb Clin Neurol. 2017;141:675–683.


Singer M., Deutschman C.S., Seymour C.W., et al. The third international consensus definitions for sepsis and septic shock (Sepsis-3). JAMA. 2016;315(8):801–810.



Shunts, Third Ventriculostomy, Ventriculoperitoneal Shunts



Keywords


VP shunt, shunts, third ventriculostomy



  1. I. Ventriculoperitoneal (VP) shunts are used primarily for the treatment of hydrocephalus. They are favored in infants and growing children because extra tubing can be left in the peritoneal cavity, allowing for growth and extending the time between shunt revisions.
  2. II. Ventriculojugular (VJ) and ventriculoatrial shunts are also used for the treatment of hydrocephalus and may be used after major growth is completed. Complications (thrombi, endocarditis, septic or tubing emboli, and arrhythmias) are more frequent and serious than with VP shunts, and thus these shunts are less used.
  3. III. Ventriculopleural (VPL) shunts are a second line option for treatment of adult hydrocephalus cases in which VPS are unsuitable or contraindicated. VPL shunts have high revision rate, and complications include pleural effusions, pneumothorax, empyema, and overdrainage.
  4. IV. Endoscopic third ventriculostomy is a newer method of approaching noncommunicating hydrocephalus that affects the third ventricle, particularly in the treatment of colloid cysts. This procedure uses an endoscope from a frontal burr hole to traverse the lateral ventricle and foramen of Monro and then enter the third ventricle to create a fistula between the third ventricle and the subarachnoid space.
  5. V. Lumboperitoneal shunts are useful in communicating hydrocephalus, particularly normal-pressure hydrocephalus. Similarly, a lumbar drain can be used for temporary, constant relief of cerebrospinal fluid (CSF) pressure for the treatment of acute surgical complications. An intrathecal pump, as in the chronic administration of baclofen, can be placed in the spinal canal for more direct and efficacious treatment of spasticity.
  6. VI. External ventriculostomy (external ventricular drains [EVDs]) temporary shunts, placed in the lateral ventricles, are useful immediately after cranial surgical procedures when CSF protein level is very high. They are also used to measure and control intracranial pressure (ICP) in traumas or acute intracranial hemorrhage (ICH) when there is debris in the CSF.
  7. VII. Ventricular access devices (Ommaya reservoir) are also available to monitor ICP, provide central nervous system (CNS) antimicrobial treatment access, and treat CNS cancers with chemotherapy. They directly access the lateral ventricle from a frontal burr hole.

Complication rates for VP shunts range from 4% to 30% in the literature, whereas endoscopic ventriculostomy yields a complication rate as high as 40%.


Shunt Malfunction


Classic symptoms of shunt dysfunction in older children and adults are headache, lethargy, nausea, and vomiting. Gradual shunt malfunction may come to medical attention as impaired school performance, irritability, or personality change. Infants may have irritability, poor feeding, vomiting, and an abnormal shrill cry. Children with repeated episodes of shunt malfunction generally come to medical attention in a similar manner with each episode.



  1. I. Mechanical malfunction can be due to disconnection, breakage, or obstruction, including a ventricular catheter plugged with glia or choroid plexus, a valve plugged with high-protein CSF or debris, or a distal catheter plugged with thrombus (VJ) or omentum (VP).

Evaluation includes several steps: (1) Pump the valve. Difficulty with compression of the valve (“pumps hard”) suggests distal obstruction; slow refill suggests proximal obstruction or slit ventricles. Even if the shunt pumps, it may not be working properly. (2) Palpate the shunt tubing for any interruption. (3) Obtain a shunt series. Obtain plain x-rays of the entire shunt system (reservoirs and pumps may be radiolucent) to look for interruption and a noncontrasted head computed tomography (CT) scan to assess ventricular size (old films are invaluable for comparing ventricular size). (4) Tap the shunt (Huber needle only) for CSF pressure (if obstructed proximal to reservoir, measured pressure will not be elevated) and CSF examination. More than 90% of shunt failures occur in the first 3 months. In uncomplicated shunt placements, 6- to 12-month postoperative CT should be scheduled.



  1. II. Shunt infection: A shunt tap is not always necessary when a fever develops in a child with a shunt. Upper respiratory infection, otitis media, pharyngitis, urinary tract infection, and gastroenteritis are frequent causes of febrile illness in any child, including those with shunts. A tap should be performed if the child is lethargic, unusually irritable, photophobic, or has neck stiffness. A shunt tap should also be considered if there is a history of similar presentation with a previous shunt infection or if there is unexplained fever or leukocytosis. Staphylococcus epidermidis and Staphylococcus aureus are the two most common types of infective agents. Although intrathecal antibiotics may be successful, removal of an infected shunt is usually necessary for effective treatment.
  2. III. Other CNS complications of shunts include meningitis, seizures, hematomas, and hygromas. Asymptomatic bilateral subdural effusions are common (30%) in VP shunts and can occur secondary to a siphoning effect of the shunt, causing excess CSF to be drained. Programmable valves lessen this complication. Peritoneal complications include ascites and cyst formation, perforation of viscus or abdominal wall, infection with obstruction of the distal end of the catheter, and peritoneal metastases from CNS tumors (e.g., medulloblastoma). Other complications include soft tissue infection along the shunt tract and pressure necrosis of the skin.

Fig. 60 shows the major components of typical shunt systems.


Fig. 60
Figure 60 Typical shunt system (many variations exist).


Reference


Craven C., Asif H., Farrukh A., et al. J Neurosurg. 2017;126(6):2010–2016.



Sickle Cell Disease



Keywords


Sickle cell disease, sickle cell anemia, neurologic complications/manifestations of sickle cell disease, meningitis, moyamoya, stroke, PRES, intracranial hemorrhage, aneurysm, transfusion


Sickle cell disease (SCD) is a group of inherited red blood cell disorders characterized by the presence of two beta-globin gene mutations, at least one of which being a sickle mutation. The most common forms of SCD are sickle cell anemia (SCA) (homozygous sickle mutation; HbSS), sickle beta thalassemia (HbS/B-Th), and hemoglobin SC disease (HbSC). Conversely, sickle cell trait is defined as a carrier condition in which one beta-globin allele carries the sickle mutation and the other allele is completely normal (HbAS). In general, sickle cell trait is not symptomatic.


Sickle hemoglobin tends to polymerize when deoxygenated, resulting in damage of the red blood cells (RBC); this ultimately leads to hemolytic anemia and vascular obstruction/vasoocclusion. Virtually every organ can be affected; therefore SCD is considered a multisystem disorder. The neurologic complications of SCD include stroke (ischemic and hemorrhagic), posterior reversible encephalopathy syndrome (PRES), seizures, meningitis, headache, intracranial aneurysm, moyamoya syndrome, neurocognitive dysfunction, retinal detachment, and proliferative retinopathy.



  1. 1. Stroke (ischemic and hemorrhagic):

    1. a. Patients with SCD are at high risk for stroke (ischemic and hemorrhagic), especially those with SCA (HbSS) and HbS/beta0-thalassemia.
    2. b. The prevalence of stroke (ischemic and hemorrhagic) in SCA is estimated as 11% by age 20, 15% by age 30, and 24% by age 45.
    3. c. The overall incidence is approximately 0.5 per 100 patient-years. The incidence of ischemic stroke in SCA is higher in children, adolescents, and elderly patients. Conversely, the incidence of hemorrhagic stroke is highest in individuals aged 20 to 29 years.
    4. d. Hemorrhagic stroke accounts for one-third of SCD-related strokes and is associated with a 25% mortality rate.
    5. e. The most common risk factors for ischemic stroke comprise prior transient ischemic attack (TIA), rate of and recent acute chest syndrome, high SBP, low steady state hemoglobin level, silent infarct, and high mean velocity (> 200 cm/s) on transcranial Doppler (TCD).
    6. f. The most common risk factors for hemorrhagic stroke comprise high steady state white blood cells (WBC) and low steady state hemoglobin levels, as well as presence of aneurysm. Other suggested risk factors include recent blood transfusion and treatment with steroids or nonsteroidal anti-inflammatory drugs (NSAIDs).
    7. g. Most ischemic strokes are secondary to large vessel vasculopathy involving the supraclinoid internal carotid artery (ICA) and proximal middle and anterior cerebral arteries. The most common topography for cerebral infarctions includes large vessel territory, borderzone regions, and punctate lesions in the deep white matter. Silent infarcts, found in approximately one-fifth of these patients, are usually located within deep white matter.
    8. h. Most intracranial hemorrhages (ICHs) (intraparenchymal, subarachnoid hemorrhage (SAH), intraventricular, or a combination) do not have an identified etiology. However, when the etiology is known, it is usually SAH—often secondary to intracranial aneurysm. Other causes include hemorrhagic transformation of an ischemic infarct, cerebral venous thrombosis, and moyamoya syndrome. Importantly, the presence of ICH does not exclude the possibility of a concurrent stroke.
    9. i. Acute management of ischemic stroke in patients with SCD should include optimal hydration, correction of hypoxemia, correction of systemic hypotension, and blood exchange to reduce the percentage of HbS levels to less than 30% with a target hemoglobin of approximately 10g/dL. Intravenous recombinant tissue plasminogen activator (IV r-TPA) for patients with known SCD (children and adults) and an acute ischemic stroke is not well established.
    10. j. Acute management of ICH in patients with SCD does not differ from ICH in the general population—because there is a lack of formal evidence on the treatment of ICH in SCD.
    11. k. Work-up should include neurovascular imaging to look for large vessel disease, aneurysm, and moyamoya syndrome. In the case of ICH, angiography should be performed if initial vascular imaging (magnetic resonance angiography/computed tomography angiography [MRA/CTA]) is unrevealing. Importantly, the use of contrast may increase the risk of stroke. Magnetic resonance venography (MRV) should be obtained if cerebral venous thrombosis (CVT) is suspected. In addition to standard stroke labs, complete blood count (CBC), reticulocyte count, percent hemoglobin S, and type and crossmatch should also be obtained. These patients should concurrently undergo thorough investigation for other possible causes of stroke (such as cardiac arrhythmia and hypercoagulability).
    12. I. Primary and secondary ischemic stroke prevention in children with SCD involves chronic transfusion therapy. Children with SCD and high TCD velocity (> 200 cm/sec) should receive chronic transfusions with a goal of reducing HbS to less than 30%. Similarly, children with SCD who have had an ischemic stroke should receive chronic transfusion therapy; these patients should also be evaluated for hematopoietic stem cell transplantation and/or hydroxyurea. Primary and secondary ischemic stroke prevention in adults has been understudied. Secondary ICH prevention relies on identifying and treating underlying causes—such as aneurysm. Cerebral revascularization may decrease the risk of recurrent stroke in patients with moyamoya syndrome.

  2. 2. PRES

    1. a. PRES is characterized by confusion, headaches, visual symptoms, and seizures. Neuroimaging shows white matter changes predominantly in the posterior topography (occipital and parietal regions; frontal lesions may occur). This syndrome is associated with multiple conditions such as hypertension and immunosuppressive therapy, as well as SCD. Importantly, PRES can mimic stroke; differentiating these two entities is paramount and may be assisted by diffusion-weighted imaging.

  3. 3. Seizures

    1. a. Seizures and epilepsy are 2 to 3 times more common in patients with SCD compared with nonsickle populations. Male gender and history of dactylitis are associated with a higher risk of developing epilepsy. (Dactylitis is characterized by sudden onset of severe pain associated with warmth and edema affecting the hands and/or feet. It is caused by bone marrow infarction of the carpal/tarsal bones and phalanges secondary to vascular blockage, and it is often the initial presentation in infants. An episode may last 1 to 4 weeks.) Seizures in SCD are believed to be secondary to a combination of factors including stroke/ICH and infection of the CNS, as well as other SCD-related mechanisms that potentially lead to (focal) cerebral hypoperfusion. If antiseizure medications are started, folic acid supplementation should be optimized.

  4. 4. Meningitis

    1. a. Patients with SCD are more susceptible to infections, especially from encapsulated bacteria—such as Streptococcus pneumoniae, Haemophilus influenzae, and Neisseria meningitidis—mainly due to functional asplenia caused by splenic infarction. These infections include life-threatening bacterial meningitis. Patients with SCD and suspected meningitis should undergo lumbar puncture, blood cultures should be drawn, and broad-spectrum antibiotics should be started. The latter are generally a combination of a third-generation cephalosporin and vancomycin, as well as ampicillin (if > 50 years of age).

  5. 5. Headache

    1. a. Headache in SCD may be secondary to a variety of severe conditions including stroke, ICH, CVT, and meningitis. Headache may also be due to pain crisis or rebound cephalgia (because chronic pain medication use is common). Therefore, although benign causes of headache predominate, these patients should undergo thorough evaluation.


References


Demaerschalk B.M., Kleindorfer D.O., Adeoye O.M., et al. Scientific rationale for the inclusion and exclusion criteria for intravenous alteplase in acute ischemic stroke: a statement for healthcare professionals from the American Heart Association/American Stroke Association. Stroke. 2016;47:581–641.


Ohene-Frempong K., Weiner S.J., Sleeper L.A., et al. Cerebrovascular accidents in sickle cell disease: rates and risk factors. Blood. 1998;91:288–294.



Sleep Disorders



Keywords


Sleep disorders, insomnia, parasomnia, REM, NREM, sleep disorders, Restless Leg, Periodic limb movements


The seven major categories of sleep disorders are insomnia, sleep-related breathing disorders, central disorders of hypersomnolence, circadian rhythm sleep-wake disorders, parasomnias, sleep-related movement disorders, and other sleep disorders.



  • I. Insomnia is the most common sleep disorder and comes in three distinct types.

    •  Short-term insomnia: This is a problem related to sleep initiation or sleep maintenance (despite adequate opportunity and circumstances for sleep) and daytime sleepiness, lasting less than 3 months. It is often associated with a stressor, and can resolve when the stressor is removed and/or adequate coping develops.
    •  Chronic insomnia: This is a problem with sleep initiation or maintenance (despite adequate opportunity and circumstances for sleep) and daytime sleepiness occurring 3 times a week for 3 months or more.
    •  Other insomnia: These are insomnia that do not meet the criteria of the first two.
    •  Dyssomnia: This is a disorder of initiating and maintaining sleep. It is characterized by insomnia, excessive sleepiness, or abnormal circadian cycle.

  • II. Sleep-Related Breathing Disorders: These are abnormal respirations that occur during sleep in adults or children. They comprise four types.

    •  Central Sleep Apnea: This comprises: (1) with Cheyne-Stokes breathing, (2) without Cheyne-Stokes breathing, (3) high altitude periodic breathing due to medication or substance use, and (4) primary central sleep apnea.
    •  Obstructive Sleep Apnea (OSA): This is defined as having 15 or more respiratory events per hour, even in the absence of an associated symptom or comorbid disorders. In adults with comorbid conditions such as hypertension, coronary artery disease, atrial fibrillation, congestive heart failure, stroke, diabetes, cognitive and mood disorders; or if there are signs or symptoms including excessive sleepiness, fatigue, and/or insomnia, the diagnosis of OSA is made when there are five or more predominant obstructive respiratory events per hour.
    •  Sleep-related hypoventilation: Defined as elevated arterial partial pressure of carbon dioxide (PaCO2). The criteria for diagnosis is PaCO2 > 45 mm Hg. Examples include obesity hypoventilation, congenital central alveolar hypoventilation, late onset central hypoventilation with hypothalamic dysfunction, idiopathic, due to medication or substances, or due to a medical disorder.

  • III. Central Disorders of Hypersomnolence: These conditions have a primary complaint of daytime excessive sleepiness not due to another sleep disorder. Excessive sleepiness in this case is defined as daily episodes of irrepressible need to sleep or daytime lapse into sleep.

    •  Narcolepsy type 1: Described as having cataplexy with or without hypocretin-1 deficiency, although cerebrospinal fluid (CSF) hypocretin-1 < 110 pg/mL is diagnostic; or a mean sleep latency of ≤8 minutes and two sleep onset rapid eye movement periods (SOREMP) within 15 minutes of sleep onset on an MSLT (and/or the overnight polysomnogram).
    •  Narcolepsy type 2: Meeting the criteria of narcolepsy type 1 except for the absence of CSF hypocretin-1 level and cataplexy.
    •  Idiopathic hypersomnia: this is a subjective sleepiness with an MSLT <8 min and less than 2 SOREMPs, without cataplexy and without hypocretin 1 deficiency.
    • Other Central Disorders of Hypersomnolence
    •  Kleine-Levin Syndrome
    •  Hypersomnia due to medical disorder
    •  Hypersomnia due to medication or substance use
    •  Hypersomnia associated with psychiatric disorder
    •  Insufficient sleep syndrome

  • IV. Circadian Rhythm Sleep-Wake Disorders: This is a group of chronic or recurrent sleep disturbances due to altered circadian system. There is a misalignment between the environmental cues and the individual sleep wake cycle. They are a common cause of excessive daytime sleepiness.

    •  Time zone change (also known as “jet lag”)
    •  Shift work syndromes
    •  Delayed/advanced sleep phase syndromes
    •  Non-24 hour sleep wake rhythm disorder with fluctuating periods of insomnia and/or excessive sleepiness: caused by intrinsic circadian pacemaker out of sync with 24 hour day cycle.
    •  Circadian rhythm disorders due to medical, psychiatric or neurologic disorders
    •  Irregular sleep wake rhythm disorders

  • V. Parasomnias are abnormal undesired physiologic or behavioral events occurring at initiation of sleep, during sleep, or during arousal from sleep.

    •  Non-Rapid Eye Movement (NREM)-related parasomnias: NREM-related parasomnias are arousal disorders that include sleepwalking, confusional arousals, and sleep terrors, in contrast to nightmares, which occur during rapid eye movement (REM) sleep. These episodes are recurrent, and include (1) incomplete awakening, (2) absent or inappropriate responsiveness, (3) limited or no cognition of a dream, and (4) partial or complete amnesia to the episode.
    •  Rapid Eye Movement (REM) associated Parasomnias: These are associated with REM sleep and include nightmares, sleep paralysis, REM sleep behavior disorder, and sleep related painful erections.
    •  Other Parasomnias:

      •  sleep enuresis and bruxism
      •  nocturnal paroxysmal dystonia
      •  primary snoring
      •  benign neonatal myoclonus
      •  sleep-related abnormal swallowing
      •  sleep enuresis
      •  exploding head syndrome
      •  parasomnia associated with medical disorders
      •  parasomnia due to a medication or substance

  • VI. Sleep-related movement disorders: These are described as simple, stereotypic movements that disturb sleep. Dysesthesia during wakefulness is a primary symptom.

    •  Restless Leg Syndrome (Willis-Ekbom Disease)—primary description is an urge to move the legs and/or presence of discomfort at rest, that is relieved with movement. There is an associated circadian component as it primarily occurs at night or in the evening, causing distress and impairment of sleep.
    •  Periodic Limb Movement Disorder—diagnosed by polysomnography which notes frequent limb movements of more than 15 times per hour in adults and more than 5 in children.
    •  Other sleep related movement disorders include:

      •  Sleep-related cramps
      •  Sleep-related bruxism (teeth grinding)
      •  Sleep-related rhythmic movement disorder
      •  Benign sleep myoclonus of infancy
      •  Propriospinal myoclonus at sleep onset
      •  Sleep-related movement disorder due to a medical disorder
      •  Sleep-related movement disorder due to medication or substance

  • Treatment of Sleep Related Disorders:

    •  Associated medical or psychiatric conditions should be treated.
    •  General management of insomnia includes optimizing the patient’s “sleep hygiene” as follows:

      •  Behavioral therapies:

        1. (1) Sleep hygiene and stimulus control
        2. (2) Wake and sleep at the same time each day (including weekends)
        3. (3) Use the bed only for sleep and sex
        4. (4) Leave the bed if not asleep within 10 minutes of lying down in bed
        5. (5) Avoid heavy exercise or large meals just before bedtime
        6. (6) Avoid daytime napping (sleep restriction)
        7. (7) Make sure the bedroom is not too warm or cold
        8. (8) Exercise regularly, and
        9. (9) discontinue alcohol, caffeine, cigarettes, and psychoactive drugs.

      •  Other treatments include: biofeedback, sleep restriction therapy, and cognitive behavioral therapy.
      •  Approved medications include:

        •  Short-acting benzodiazepines that may offer temporary adjunctive benefit, but their long-term use is not recommended.
        •  Other sedatives, including melatonin agonists ramelteon, suvorexant (orexin agonist), zalephon, zolpidem, eszopiclone and diphenhydramine, may be used judiciously.
        •  Antidepressants such as doxepin, amitriptyline, trazodone can be used.
        •  Management of parasomnias and abnormal movements are complex and have an overarching goal to keep patient safe.

      •  Work-up includes: polysomnography.
      •  In Restless Leg Syndrome, labs for iron deficiency should be checked.
Aug 12, 2020 | Posted by in NEUROLOGY | Comments Off on S
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