Preoperative Diagnostics and Indication for Surgery

and Uwe Spetzger1



(1)
Department of Neurosurgery, Klinikum Karlsruhe, Karlsruhe, Baden-Württemberg, Germany

 



Past medical history and clinical examination give information about radicular and myelopathic symptoms and help to assess the acuity of clinical complaints and thus the urgency of a possible surgical treatment. MRI is the imaging method of first choice in cases of degenerative diseases of the cervical spine with neurological symptoms. The meaning of pre- and postoperative functional X-ray imaging has continuously increased because of the growing number of dynamic implants for total disc replacement. With the help of CT scans especially bony driven stenoses of the cervical spinal canal can be diagnosed in detail. A myelogram is useful in selected cases of multilevel narrowing of the spinal canal, especially in cases of previous surgeries. If it is impossible to confirm or exclude the indication for surgery by means of clinical complaints and imaging findings, it might be useful to consider electrophysiological techniques for the clinical diagnosis.


4.1 Past Medical History and Clinical Examination



4.1.1 General Considerations


The clinical symptoms of the patient are first and foremost when indicating surgery or not. There is a consensus that in cases of an acute palsy (hours or a few days) of muscles of the upper limb of grade 3 or less due to cervical disc herniation, surgical treatment is urgently indicated. In the rare case of acute tetraparesis (incomplete in most cases), there is even an emergency indication for surgical decompression of the spinal cord.

In the daily clinical routine, most patients suffer from recurrent neck pain and brachialgia or headaches as well as from sensory disorders of the upper limbs. Thus, the main problem is the acute or chronic pain. In some of the patients, clinical examination shows a slight paresis of a certain muscle of the upper limb. If duration, intensity and resistance to therapy of clinical complaints heavily impair the patient’s quality of life, elective surgical treatment can be recommended.

In cases of long-lasting compression of neural structures (months or years), the development of a somatoform disorder is possible due to the activation of the pain memory. That means that even after a decompression of nerves, thus after removing the morphological reason for the pain, a perception of pain persists. This fact should be considered in cases of complaints over months when the arguments for surgical and non-surgical treatment are balanced.


4.1.2 Radicular Symptoms



4.1.2.1 Radicular Pain Syndrome


An acute disc herniation with compression of ventral and dorsal spinal nerve roots causes a radicular pain syndrome that not just affects the dermatome but also the sclerotome. In cases of the more frequent, slowly progressive spondylosis, the pain syndrome begins with a dull and gnawing pain in the neck and shoulder followed by the arm. Later paraesthesias and a sensation of numbness appear. Some patients suffer from sudden fulgurous pain that can be triggered by moving the head or coughing (Frykholm 1969).

The deep somatic pain which is often described as dull pain results from compression of the ventral root. Neuralgia with paraesthesias and numbness that radiates into fingers is the result of dorsal nerve root compression (Frykholm 1969).


4.1.2.2 Sensory Deficits


Disorders of sensation usually start distally at the fingers. There it is easy to identify the border of the affected dermatome and thus the compressed nerve root. Paraesthesias are a symptom of intermittent compression of the dorsal nerve root. They can appear in combination with hypoalgesia or hyperalgesia (Frykholm 1969). A reduced sensation of vibration (pallhypaesthesia) is considered as a sign of multiradicular compression and is mainly used to detect differential diagnoses such as polyneuropathy.


4.1.2.3 Motor Deficits


The compression of a ventral root causes paresis of a segment-indicating muscle and in some cases atrophy of muscles. Pareses with high functional consequences and acute severe motor deficits, respectively, are main indicators for surgical treatment in cases of proven cervical disc herniation. The clinical identification of nerve root compression reliably succeeds in cases of weakness of a segment-indicating muscle (O’Brien 2000):



  • C4: major and minor rhomboideus muscle


  • C5: deltoid muscle


  • C6: biceps and brachioradialis muscles


  • C7: triceps muscle


  • C8: superficial flexor digitorum, deep flexor digitorum I and II, deep flexor digitorum III and IV muscles


  • T1: opponens pollicis muscle and muscles of the hypothenar


4.1.2.4 Vegetative Disorders


Some patients with nerve root compression suffer from an increased tone of the sympathetic nervous system with consecutive vasomotoric disorders of the upper limb leading to a sensation of coldness and a change of skin colour. A cervico-cephal syndrome was described by Barré (1926). It is characterised by unilateral headaches, vertigo, sometimes tinnitus and ear pain.


4.1.3 Pathological Reflexes as a Sign of Radicular or Spinal Cord Compression


The monosynaptic muscle reflexes are diminished in cases of compression of a peripheral nerve such as hyporeflexia of the triceps reflex as a sign of compression of the C7 root. Hyperreflexia (a response far larger than considered normal) can be seen if there is a lack of central nervous inhibitory signals, e.g. very brisk response of the patellar reflex due to compression of the cervical spinal cord as a reason of disorder of the pyramidal tracts.

The polysynaptic reflexes can be reduced in cases of pyramidal tract lesions, for example, an absent abdominal reflex as a consequence of spinal cord compression due to a cervical spondylotic myelopathy.

Reduced or absent reflexes of the upper limbs can be observed in case of a cervical disc herniation (affected nerve root in brackets):



  • Biceps reflex (C6)


  • Brachioradialis reflex (C5, C6)


  • Triceps reflex (C7)


  • Trömner’s reflex (C7, C8)

Cervical spondylotic myelopathy often causes hyperactive patellar and Achilles tendon reflexes at the lower limbs as a sign of pyramidal tract disorder. Furthermore, a positive Babinski sign is noticed that is also a typical sign of pyramidal tract disorder.


4.1.4 Myelopathic Symptoms: Spondylotic Myelopathy


Spinal cord compression of a higher grade during degenerative diseases of the cervical spine often appears as chronic state in case of an osteoligamentous spinal stenosis. MR images often show a so-called myelopathy signal as a typical finding. This signal appears in sagittal T2-weighted images as an intramedullary hyperintense area caudal to the stenosis (Fig. 4.3). Typical clinical findings are hyperreflexia of the lower limbs (Sect. 4.1.3), positive Babinski sign, unstableness in coordination tests (Unterberger’s stepping test, tightrope walking test, etc.), increased tone of lower limb muscles, sustained cloni at the lower limbs, pallhypaesthesia, fine motor disorders and non-radicular loss of sensation on both hands. In rare cases patients also suffer from centrally caused vegetative disorders such as bladder and bowel incontinence.

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Nov 14, 2017 | Posted by in NEUROSURGERY | Comments Off on Preoperative Diagnostics and Indication for Surgery
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