H



H



Hallucinations



Keywords


Sensation, delirium, dementia, seizures, schizophrenia


Hallucinations can be defined as a “sensory precept without external stimulation of the relevant sensory organ.” Hallucinations may occur in any sensory modality. It is important to distinguish hallucinations from delusions, which are false, fixed beliefs that do not directly involve a sensation. Phenomena include Lilliputian (small animals or people), Brobdingnagian (giants), and autoscopic (seeing oneself from outside) characteristics, as well as palinopsia, voices, palinacusis, crawling sensations, shooting pains, smells, and other features.



  1. I. Differential diagnosis of visual hallucinations

    1. A. Ocular disorders: Hallucinations may be associated with reduced vision. These are usually formed, bright, colored images. Charles Bonnet syndrome is isolated visual hallucinations, usually of ocular causes including enucleation, cataracts, macular, choroidal, and retinal disease and vitreous traction.
    2. B. Central nervous system (CNS) disorders: Hallucinations may be due to lesions anywhere along the optic pathways and visual association cortices. They are also seen with midbrain disease (“peduncular hallucinosis”; complex forms, usually with other brainstem signs), dementias, epilepsy, and migraine. In narcoleptics, brightly colored hypnagogic hallucinations occur just before sleep, and hypnopompic hallucinations occur on awakening.
    3. C. Medical disorders: Hallucination may be seen in 40% to 75% of delirious patients; usually they are brief, nocturnal, and emotionally charged. Causes include alcohol and drug withdrawal, hallucinogens, sympathomimetics, and metabolic encephalopathies.
    4. D. Psychiatric disorders: Schizophrenia, mania or depression, and hysteria can produce hallucinations.
    5. E. Normal individuals may experience hallucinations during dreams, falling asleep, hypnosis, childhood (imaginary companion), sensory deprivation, sleep deprivation, or intense emotional experiences.

  2. II. Differential diagnosis of auditory hallucinations

    1. A. Diseases of the ears or peripheral auditory nerves
    2. B. CNS diseases: epilepsy, neoplasms, and occasionally, vascular lesions
    3. C. Toxic or metabolic: alcoholic hallucinosis, encephalopathies
    4. D. Psychiatric: schizophrenia (60% to 90% of patients), affective disorders, conversion reactions, multiple personality disorder

  3. III. Differential diagnosis of tactile, somatic, and phantom limb hallucinations

    1. A. Phantom limb is the sensation of persistent presence of an amputated extremity and is found in almost all amputees; patients usually describe the phantom limb as being numb or tingling, of normal size, correctly aligned, with peripheral areas more prominent; the sensation may recede gradually and may be painful.
    2. B. Tactile hallucinations occur commonly in patients with schizophrenia (15% to 50%) and affective disorder (25%). Formication (the sensation of insects crawling) is found in alcohol and drug withdrawal (especially sympathomimetics) and dementias.

  4. IV. Differential diagnosis of olfactory and gustatory hallucinations

    1. A. Medial temporal lobe lesions and complex partial seizures (“uncinate fits”) may produce olfactory hallucinations. They may also occur in migraine, dementias, toxic and metabolic conditions, depression, and Briquet syndrome (20% to 25% of patients).
    2. B. Gustatory hallucinations may be seen in manic-depressive illness, schizophrenia, Briquet syndrome, and partial seizures.


Reference


Trimble M.R., Cummings J.L., eds. Contemporary behavioral neurology. Boston: Butterworth-Heinemann; 1997.



Head Trauma



Keywords


Traumatic brain injury, TBI, head injury, concussion, head trauma


Epidemiology


Traumatic brain injury (TBI) is a leading cause of disability and death, affecting more than 2 million people in the United States annually. Severe TBI is defined by a Glasgow Coma Score less than 9. TBI involves an initial injury and is followed by further neurologic damage that occurs over days following the initial trauma. All geographic areas should have an organized trauma system and follow published guidelines for managing TBI.


Treatment


Initial management of the trauma patient includes ABCI: airway, breathing, circulation, and spine immobilization. Patients with severe TBI (Glasgow Coma Scale [GCS] < 9) or who are hypoxic (arterial oxygen saturation < 90%) should be intubated for airway protection and ventilatory support. The immediate goals of the initial neurologic assessment are to do a screening neurological exam; determine the severity of head injury as low, moderate, or high risk; stabilize and rule out a fracture of the cervical spine; initiate empiric treatment for increased intracranial pressure (ICP) if it is suspected; and perform an emergent CT brain and neck to rule out fractures. The goals of TBI management are to prevent secondary insults (hypoxia, hypotension) that lead to secondary neuronal injury. To date, we have no therapies that can reverse the primary neurologic injury. Maintenance of normal hemodynamic and respiratory parameters prevents secondary injury from hypotension and hypoxemia. Even a single episode of hypotension (systolic blood pressure [SBP] < 90 mm Hg) worsens outcomes in TBI, as does hypoxia (Pao2 < 60 mm Hg). Cerebral perfusion pressure (CPP = MAP – ICP, where MAP is mean arterial pressure) should be kept greater than 60 mm Hg. Hypertension associated with wide pulse pressure and bradycardia (Cushing triad) may reflect increased ICP or focal brain stem injury. Patients who “talked and deteriorated” should be assumed to have an expanding intracranial hematoma until proven otherwise.


Intracranial pressure should be monitored in comatose patients with TBI (GCS < 8). The incidence of elevated ICP increases with the depth of coma and greater neuroimaging abnormalities. There is no predictable relationship between blood pressure and ICP. Treat ICP greater than 20 mm Hg for more than 10 minutes. Hyperventilation can be used to acutely decrease elevated ICP (target arterial PCO2 of 30 mm Hg) but has no role in chronic management. Osmotic therapy with mannitol or hypertonic saline can be used to control ICP, along with ventricular CSF drainage. Hemicraniectomy should be considered in patients with life-threatening unilateral cerebral edema. Prophylactic antiepileptic drugs should be used for the first 7 days following injury. Steroids are contraindicated for use in patients with head injury. Early enteral feeding on day 1 after injury has been shown to generally improve outcomes compared with delayed feeding.


Fever should be aggressively treated over the first few days with the goal being normothermia. There is currently no proven benefit to hypothermia. Glycemic and fever control are also a priority in acute TBI. Brain tissue oxygenation (PbtO2) and jugular venous oxygen saturation (SjvO2) can be monitored to ensure adequate brain oxygenation. Low-dose anticoagulation to prevent thromboembolic disease can safely be started within 48 hours after injury. Following the initial injury, physical and cognitive rehabilitative services will likely be needed on an ongoing basis. The incidence of chronic cognitive-behavioral impairment is high.



Headache: Migraine and Other Types (See also AAN Guideline Summaries Appendix)



Keywords


Headache, migraine, tension-type headaches, cluster headaches, cephalgia


Given the range of disorders that present with headache, a systematic approach to headache classification and diagnosis is essential. Since 1988, the International Headache Society’s classification has been the accepted standard for headache diagnosis. The 2017 International Classification of Headache Disorders, third edition (ICHD-3, beta, Table 70), groups headache disorders into primary and secondary headaches. The four categories of primary headache include migraine, tension-type headache (TTH), trigeminal autonomic cephalalgias, and other primary headaches. There are also eight categories of secondary headache, and a third group that includes central and primary causes of facial pain and other headaches.



Table 70







The international classification of headache disorders, third edition (ICHD-3)

I. The primary headaches


A. Migraine


B. Tension-type headache (TTH)


C. Trigeminal autonomic cephalgias


D. Other primary headaches


II. The secondary headaches


A. Headache attributed to trauma or injury to the head and/or neck


B. Headache attributed to cranial or cervical vascular disorder


C. Headache attributed to non-vascular intracranial disorder


D. Headache attributed to a substance or its withdrawal


E. Headache attributed to infection


F. Headache attributed to disorder of homeostasis


G. Headache or facial pain attributed to disorder or cranium, neck, eyes, ears, nose, sinuses, teeth, mouth, or other facial or cranial structures


H. Headache attributed to psychiatric disorder


I. Painful cranial neuropathies and other facial pain


III. Other headache disorders (not else classified or unspecified)



Table 70


From the International Headache Society 2013.


Primary headache types


Migraine


Migraine affects approximately 18% and 6% of US women and men, respectively. Peak prevalence occurs in middle life with lower incidence in adolescents and those older than 60 years. Nearly one-third of migraineurs experience three or more attacks per month and over half report severe impairments or the need for bedrest. Chronic migraine refers to more than 3 months of 15 or more headache days, at least eight of which are migrainous. It is important to differentiate from medication-overuse headache (analgesic rebound headache), which pertains to the regular intake of ergotamines, triptans, or combination analgesics on > 10 days per month for > 3 months. Status migrainosus refers to more than 72 hours of debilitating migraine. The term probable migraine may be used in patients with migrainous features not meeting diagnostic criteria for migraine.


Migraine is classified into five major categories:



  1. I. Migraine without aura

    1. A. ≥ 5 attacks fulfilling criteria B through D
    2. B. Headache attacks lasting 4 to 72 hours (untreated or unsuccessfully treated)
    3. C. ≥ 2 of the following four characteristics:

      1. 1. Unilateral location
      2. 2. Pulsating quality
      3. 3. Moderate or severe pain intensity
      4. 4. Aggravation by or causing avoidance of routine physical activity (e.g., walking or climbing stairs)

    4. D. During headache ≥ 1 of the following:

      1. 1. Nausea and/or vomiting
      2. 2. Photophobia and phonophobia

    5. E. Not better accounted for by another ICHD-3 diagnosis

  2. II. Migraine with aura
    Aura refers to the complex of symptoms usually occurring prior to the onset of headache; however, symptoms may follow the initial pain phase and even continue into the headache itself. Auras may occur in the absence of headache. A diagnosis of persistent aura without infarction may be made when aura symptoms last ≥ 1 week if neuroimaging is negative for infarction. Conversely, migrainous infarction may be diagnosed when aura symptoms are attributed to a demonstrated ischemic brain lesion. There is a two-fold increased risk in patients suffering from migraine with aura; however, these are not migrainous infarctions. Seizures may be triggered by migraine with aura (migraine aura-triggered seizure).

    1. A. ≥ 2 attacks fulfilling criteria B and C
    2. B. ≥ 1 of the following fully reversible aura symptoms:

      1. 1. Visual (most common aura, e.g., zigzag, flashing lights, spots, or lines)
      2. 2. Sensory (second most common aura, e.g., paresthesias, numbness)
      3. 3. Speech and/or language
      4. 4. Motor (Dx: hemiplegic migraine)
      5. 5. Brainstem (e.g., dysarthria, vertigo, tinnitus, hypacusis, diplopia, ataxia, decreased level of consciousness)
      6. 6. Retinal (monocular positive and/or negative visual phenomenon, e.g., scintillations, scotomata, or blindness)

        • • Other causes of monocular visual loss, including transient ischemic attack (TIA), optic neuropathy, and retinal detachment, must be ruled out

    3. C. ≥ 2 of the following:

      1. 1. At least one aura symptom spreads gradually over 5 or more minutes, and/or two or more symptoms occur in succession
      2. 2. Each individual aura symptom lasts 5 to 60 minutes
      3. 3. At least one aura symptom is unilateral
      4. 4. The aura is accompanied, or followed within 60 minutes, by headache

    4. D. Not better accounted for by another ICHD-3 diagnosis, and transient ischemic attack has been excluded

  3. III. Familial hemiplegic migraine (FHM)

    1. A. Mutations identified in CACNA1A, ATP1A2, and SCN1A genes
    2. B. Aura includes motor weakness
    3. C. First- or second-degree relative has hemiplegic migraines
    4. D. Mistaken for epilepsy
    5. E. May be triggered by head trauma
    6. F. Approximately half of FHM families have chronic progressive cerebellar ataxia.
    7. G. If no family history, then diagnosis is sporadic hemiplegic migraine.

  4. IV. Episodic syndromes ± aura

    1. A. Formerly known as childhood periodic syndromes, but may be seen in adults
    2. B. All are characterized by normalcy between episodes
    3. C. Diagnoses include:

      1. 1. Recurrent gastrointestinal disturbance

        • • Attacks of abdominal pain/discomfort and/or nausea/vomiting

      2. 2. Cyclic vomiting syndrome

        • • Stereotyped episodic nausea/vomiting ± pallor and lethargy
        • • Mainly seen in children

      3. 3. Abdominal migraine (longer lasting and more severe than recurrent gastrointestinal disturbance)

        • • Recurrent moderate/severe midline abdominal pain with vasomotor symptoms, nausea/vomiting
        • • Lasts 2 to 72 hours
        • • Normal between episodes
        • • No headache during episode

      4. 4. Benign paroxysmal vertigo

        • • Sudden and resolving vertigo, no loss of consciousness
        • • At least one of the following: nystagmus, ataxia, vomiting, pallor, fearfulness

      5. 5. Benign paroxysmal torticollis

        • • Recurrent head tilt to one side ± slight rotation
        • • Usual onset in the first year of life
        • • At least one of the following: nystagmus, ataxia, vomiting, pallor, fearfulness
        • • Remits spontaneous after minutes-days

Tension-type Headache (TTH)


TTH is the most common type of primary headache, with a lifetime prevalence ranging from 30% to 78%. The ICHD-3 (beta) criteria distinguishes three subtypes: infrequent episodic TTH with headache episodes ≤ 1 day per month, frequent TTH with headache episodes on 1 to 14 days per month, and chronic TTH with headache ≥ 15 days per month, perhaps without recognizable episodes. A diagnosis of probable tension-type headache can be made when headache fulfills all but one of the criteria for TTH and does not fulfill criteria for migraine without aura.



  1. I. Infrequent episodic TTH

    1. A. ≥ 10 episodes of headache on < 1 day per month on average (<12 days per year) and fulfilling criteria B-D
    2. B. Lasting 30 minutes to 7 days
    3. C. ≥ 2 of the following:

      1. 1. Bilateral
      2. 2. Pressing/tightening (non-pulsating) quality
      3. 3. Mild/moderate intensity
      4. 4. Not aggravated by routine physical activity (e.g., walking or climbing)

    4. D. Both of the following:

      1. 1. No nausea or vomiting
      2. 2. No coincidence of photophobia and phonophobia (may have one or the other)

    5. E. Not better accounted for by another ICHD-3 diagnosis

  2. II. Frequent episodic TTH is ≥ 10 episodes of headache occurring on 1 to 14 days per month for > 3 months on average (≥ 12 and < 180 days per year) and fulfilling criteria B-D shared by infrequent episodic TTH
  3. III. Chronic TTH is headache occurring ≥ 15 per month for > 3 months on average (≥ 180 days per year) and fulfilling criteria B-D shared by infrequent episodic TTH

Trigeminal Autonomic Cephalalgias


This group of primary headache disorders is characterized by trigeminal activation coupled with parasympathetic activation.



  1. I. Cluster Headache
    The prevalence is ~ 1 in 500 individuals, and it is approximately three times more prevalent in men than women with no significant differences in clinical presentation. Onset typically occurs after age 30. Patients usually experience cluster periods (on average, one or two 6- to 12-week periods per year) alternating between longer periods of remission. During a cluster period, there is usually 1 to 3 attacks in a 24-hour period. It commonly wakes people from sleep. Approximately 90% of patients have this episodic form. The remainder suffer from the chronic form, during which cluster periods last for more than 1 year without remission or with remission periods lasting < 1 month.

    1. A. ≥ 5 attacks fulfilling B-D
    2. B. Severe or very severe unilateral orbital, supraorbital, and/or temporal pain lasting 15 to 180 minutes (untreated)
    3. C. ≥ 1 of the following:

      1. 1. ≥ 1 of the following ipsilateral to the headache:

        • • Conjunctival injection and/or lacrimation, nasal congestion and/or rhinorrhea, eyelid edema, forehead and facial sweating/flushing, sensation of fullness in the ear, miosis and/or ptosis

      2. 2. Sense of restlessness or agitation

    4. D. Attacks frequency Q48 hours to 8× per day for more than half of the time when the disorder is active

  2. II. Paroxysmal hemicrania
    May differentiate between episodic (attack periods of 7 days to 1 year, separated by pain-free periods ≥ 1 month) and chronic where paroxysms occur for ≥ 1 year without remission or with remission period of < 1 month.

    1. A. ≥ 20 attacks fulfilling B-E
    2. B. Severe unilateral orbital, supraorbital, and/or temporal pain lasting 2 to 30 minutes
    3. C. ≥ 1 of the following:

      • • Conjunctival injection and/or lacrimation, nasal congestion and/or rhinorrhea, eyelid edema, forehead and facial sweating/flushing, sensation of fullness in the ear, miosis and/or ptosis

    4. D. Attack frequency ≥ 5 per day for more than half of the time
    5. E. Attacks are prevented absolutely by therapeutic doses of indomethacin

  3. III. Short-lasting unilateral neuralgiform headache attacks

    1. A. ≥ 20 attacks fulfilling B-D
    2. B. Moderate/severe unilateral head pain, with orbital, supraorbital, temporal, and/or other trigeminal distribution, lasting 1 to 600 seconds and occurring as a stabbing pain (single/series) or in a saw-tooth pattern
    3. C. ≥ 1 of the following ipsilateral to the pain:

      • • Conjunctival injection and/or lacrimation, nasal congestion and/or rhinorrhea, eyelid edema, forehead and facial sweating/flushing, sensation of fullness in the ear, miosis and/or ptosis

    4. D. Attack frequency ≥ 1 per day for more than half of the time when the disorder is active

Within this headache type, there are short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT) and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA), both of which may be episodic (attacks periods lasting 7 days to 1 year, separated by pain-free periods lasting ≥ 1 month) or chronic (attack periods > 1 year without remission or with remission lasting < 1 month). SUNCT headaches are accompanied by both conjunctival injection and lacrimation, while SUNA headaches may be accompanied by one or neither of these. A diagnosis of hemicrania continua can be made when present for >3 months with exacerbations of moderate or greater intensity. This condition is also absolutely responsive to indomethacin.


Other Primary Headache Disorders


This group of miscellaneous primary headache disorders includes some mimics of potentially serious secondary headaches, which need to be carefully evaluated by imaging or other appropriate tests. Diagnosis of these headaches may only be made in the absence of any intracranial disorder.



  1. I. Primary cough headache
    Precipitated by coughing or other Valsalva maneuver, but not by prolonged physical exercise. Neuroimaging, with special attention to the posterior fossa and base of the skull, is mandatory to rule out secondary forms of cough headache. Normally occurs over the age of 50.
  2. II. Primary exercise headache
    Precipitated by any form of exercise. Normally alleviates when exertion is finished. Typically occurs under the age of 50.
  3. III. Primary headache associated with sexual activity

    1. A. Usually starts as dull bilateral ache and lasts 1 minute to 24 hours with severe intensity and/or up to 72 hours with mild intensity.
    2. B. ≥ 1 of the following

      1. 1. Increasing headache intensity with increasing sexual excitement
      2. 2. Abrupt explosive intensity just before or with orgasm

    3. C. With the first episode it is mandatory to rule out secondary causes such as subarachnoid hemorrhage and reversible cerebrovascular vasoconstriction syndrome.

  4. IV. Primary thunderclap headache

    1. A. High-intensity headache of abrupt onset (< 1 minute to max intensity).
    2. B. Lasts ≥ 5 minutes
    3. C. Important alternate diagnoses to rule out include:

      • • Subarachnoid hemorrhage, unruptured vascular malformation (mostly aneurysm), cerebral venous sinus thrombosis, cervicocephalic arterial dissection, pituitary apoplexy, acute hypertensive crisis, spontaneous intracranial hypotension, meningitis, embolic cerebellar infarcts, colloid cyst of the third ventricle, and reversible cerebral vasoconstriction syndromes.

  5. V. Cold-stimulus headache

  6. VI. External-pressure headache

  7. VII. Primary stabbing headache

  8. VIII. Nummular headache

  9. IX. Hypnic headache

  10. X. New daily persistent headache

Headache therapy


Three components of a systematic approach to treating headache are psychological, physical, and pharmacologic. Psychological therapy involves reassurance and counseling, as well as stress management, relaxation therapy, and biofeedback as appropriate. Physical therapy involves identifying headache triggers, such as diet, hormone variations, and stress, and whether alteration may be helpful in treating selected cases. The patient should record a headache calendar documenting the occurrence, severity, and duration of headaches; the type and efficacy of medication taken; and any triggering factors. Pharmacotherapy can be divided into two approaches: abortive and prophylactic.


Abortive (Acute) Therapy of Migraine


Migraine-specific agents (e.g., triptans, dihydroergotamine [DHE], ergotamine) are used in patients with more severe migraine and in those whose headaches respond poorly to nonsteroidal anti-inflammatory drugs (NSAIDs) or combination of analgesics. Select a non-oral route of administration for patients whose migraines present early with significant nausea or vomiting.



  1. I. Routine analgesics (aspirin, acetaminophen, and NSAIDs, including ibuprofen, naproxen, indomethacin, etc.) are given for less severe headaches. Ketorolac may be used for more severe headaches.
  2. II. Triptans (oral, intranasal, subcutaneous injection)

    1. A. Good first-line therapy for severe migraine
    2. B. Contraindicated in pregnancy, patients with hemiplegic migraine, or migraine with brainstem aura, or those with uncontrolled hypertension, prior stroke, or MI.
    3. C. Examples: almotriptan, eletriptan, frovatriptan, naratriptan, rizatriptan, sumatriptan, zolmitriptan.
    4. D. If symptoms persist after first dose, a second dose 2 hours later may/may not be beneficial.

  3. III. Narcotic analgesics should be avoided (especially as first-line treatment) but useful for occasional, severe headaches.
  4. IV. Ergotamine (oral form less effective than rectal or parenteral administrations)

    1. A. Less commonly used
    2. B. Contraindicated in pregnancy
    3. C. Dosing strategy

      1. 1. Oral

        • • Symptom recognition: Ergotamine tartrate 2 mg by mouth
        • • 1 hour later: Repeat first dose with an oral analgesic-caffeine combination

      2. 2. Rectal

        • • Aura onset: 1 to 2 mg rectal suppository of ergotamine tartrate
        • • 1 hour later: Repeat first dose

      3. 3. Dihydroergotamine (intravenous, intramuscular, subcutaneous, nasal spray) (Table 71)

        Table 71







        Typical emergency department treatment protocol for severe headache
        Steps to be followed in succession separated by 15–20 min

        1. IV fluids (normal saline 2–3 L bolus or 80–100 cc/hr while patient is in emergency department)


        2. IV diphenhydramine 12.5–25 mg


        3. IV metoclopramide or prochlorperazine 10 mg


        4. IV magnesium sulfate 500–1000 mg


        5. IV ketorolac 30 mg


        6. If no improvement:


        • IV sodium valproate (500 mg), IV levetiracetam (500 mg), or IV methylprednisolone (200 mg)


        7. IV dihydroergotamine 0.5–1.0 mg if patient has not used a triptan within 24 hr and no contraindications exist

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Aug 12, 2020 | Posted by in NEUROLOGY | Comments Off on H

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