Neurologic Presentation of Spinal Tumors

Published on 02/04/2015 by admin

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Chapter 8 Neurologic Presentation of Spinal Tumors

Thomas W. Belknap, Adetokunbo A. Oyelese

INTRODUCTION

One common feature of spinal tumors is their insidious course and the frequent delay between the onset of symptoms and the diagnosis of the neoplasm. In many cases, the delay can be measured in months or even years. A major reason for the delay in diagnosis is the myriad of symptoms with which these patients present, and the overlap of these symptoms with common conditions such as degenerative spine disease. Adding to the challenge of diagnosis are a number of case reports in the literature describing spinal neoplasms with unusual clinical presentations, such as severe ear pain or subarachnoid hemorrhage.^1,² As would be expected, the most common presenting neurologic signs and symptoms of spinal tumors are dependent on their location. One way to classify the location is with respect to the dura and the spinal cord. Spinal tumors can be located in the intramedullary, intradural extramedullary, or extradural space.

EXTRADURAL TUMORS

Tumors of the spine may arise from a myriad of extradural locations. They can exist within any part of the bone (including the pedicles and lamina) or in the spinal epidural space, or they may invade the spinal canal via the neural foramen. These tumors also may arise anywhere along the spinal axis, from the craniovertebral junction, down to the sacrum. The most common extradural tumors arising from the spinal vertebral column are metastatic lesions, but also include primary benign and malignant bone tumors. The most common presenting symptom is pain, whereas neurologic symptoms and signs vary depending on the spinal level affected. This pain, which is non-mechanical in etiology, tends to be constant and is not relieved by rest. It should be distinguished from mechanical spinal pain that arises from injury to the muscles, discs, joints, and ligaments of the spine that is exacerbated by activity and relieved by rest.

CRANIOCERVICAL JUNCTION

Perhaps the most interesting and initially perplexing neurologic signs and symptoms of spinal neoplasms arise from tumors in the craniocervical junction. Initially, it may be very difficult to localize the tumor based on the symptoms. About 49–66% of patients will report neck and/or suboccipital pain as primary symptoms at the time of initial presentation.^3,⁴ By the time the diagnosis is made, up to 75% will have suboccipital or neck pain, usually referable to the C2 dermatome. Dysesthesias are the second most common initial complaints, occurring in 39–54% of patients, and up to 95% of patients may complain of dysesthesias by the time of diagnosis.³ In decreasing order of frequency, the dysesthesias are found in the hands, arms, and lower extremities with up to 10.5% complaining of sensory disturbance in the face.³

Tumors compressing on the lower medulla and upper cervical spinal cord and thus affecting the descending trigeminal nucleus partly explain this finding. Cold dysesthesia of the lower limb has actually been described as a symptom pathognomonic for high cervical tumors.^5,⁶ However, this is seen in fewer than 7% of patients. Weakness is the first symptom apparent to the patient in as few as 5.3%, but it is noted at some point by 40–46% in the upper extremities and 29–42% in the lower extremities. The sensory abnormalities and weakness lead to gait disturbance in roughly half of the patients by the time of diagnosis. Bladder dysfunction is present in about 22–33% by the time of diagnosis.

Other symptoms reported by patients can be attributed to the tumor’s proximity to the brainstem. These include dysphagia, nausea and vomiting, “drop attacks,” dizziness, dysarthria, hiccups, and respiratory dysfunction. These symptoms may be caused by local effect on the brainstem itself, hydrocephalus from obstruction of cerebrospinal fluid outflow from the fourth ventricle, or even traction on the lower cranial nerves. Tumors involving the high cervical spine can cause a variety of symptoms such as hand clumsiness, Lhermitte’s sign, or respiratory dysfunction caused by diaphragm weakness.

Even though up to 20% of patients may actually have a normal neurologic examination at the time of initial clinical presentation,⁴ most patients have at least some signs of a deficit. Tetraplegia or tetraparesis can actually be found in 15–25% of patients with a craniocervical region tumor. Others may present with a monoparesis/monoplegia of the upper extremity (13–17%), hemiparesis/hemiplegia (14–15%), or paraparesis/paraplegia of the upper extremities (13–20%). The pattern of motor deficit development is quite fascinating. An alternating, rotational pattern of weakness is known to be a hallmark of craniocervical junction tumors. Typically, the weakness will begin in one upper extremity. The patient then develops weakness in the ipsilateral lower extremity. If enough time passes, the weakness may then also involve the contralateral lower extremity, and finally the contralateral upper extremity. Of course there are patients who do not display this pattern, but its presence should certainly alert the physician to the possibility of a tumor in this region. The most likely explanation for this unique finding is the decussation of the medullary corticospinal tracts near the craniocervical junction.⁷ The upper extremity motor fibers are carried medially in the corticospinal tract before the decussation. Just past the decussation, the fibers destined for upper extremities are the most lateral, with the lower extremity fibers being medially located. Therefore, a slightly lateral tumor anterior to the spinal cord will have mass effect, first on axons to the ipsilateral upper extremity motor fibers, followed by the ipsilateral lower extremity, contralateral lower extremity, and finally the contralateral upper extremity.

Sensory findings also can be quite variable in these patients. Some loss of pain and temperature is found in 37–57%.^3,⁴ Other sensory modalities affected include touch (22–30%), proprioception (27–38%), and hypalgesia of C2 (18–23%). A “cape distribution” of sensory loss can be found in 7–15%, and there is a dissociated sensory loss in 23–25%. As with motor findings, the sensory deficit is usually greater in the upper extremities compared with the lower extremities.

Other neurologic findings on examination are found in Table 8-1, which uses data from Yasuoka et al and Meyer et al.^3,⁴

Table 8-1 Neurologic Findings with Extradural Tumors at the Craniocervical Junction *

Neurologic Sign	Frequency (%)
Atrophy
Hands	15–17
Arms	7–9
Legs	1–4
Hyperreflexia	71–83
Babinski sign	57–58
Brown–Séquard	23–29
Gait disturbance	40–47
Nystagmus	13–25
Horner syndrome	4–6
Cranial nerve palsy
V	6
VII	1
VIII	1
IX	4–7
X	2–7
XI	28–32
XII	4–8