Neurology Case Challenge

[DrIreland]

The case comes from the archives of Baylor College of Medicine

History

This is a 48 year old right-handed male who presented with a 6 month history of fatigue and weight loss. For the past 6 weeks, he had noted progressive difficulty in walking, slurring of his speech, and weakness in both upper extremities. He reported difficulty in combing his hair, writing, and climbing the stairs. During the week prior to presentation, he had fallen repeatedly and was using a wheelchair. The weakness was worse on the left side. He had also noticed a "strange abnormal sensation" over his entire face, and numbness on the dorsal aspect of his left hand.

He denied pain, problems with memory or affect, visual changes, diplopia, dysphagia, breathing difficulties, or bowel and bladder dysfunction.

His past history was unremarkable. Family history includes a cousin with Addison's disease. He was previously married, but never had children. His occupation was "in the oil business". He denied drug abuse, only drinks socially, and smoked 2 packs of cigarettes per week for twenty-six years.

Physical Examination

Physical examination was within normal limits with no evidence of cardiopulmonary abnormalities, organomegaly, or arthropathy.

Neurological Examination

Mental status:
The patient was awake, alert, and oriented with a mini-mental exam of 27/30. He could not recall 2/3 objects and misspelled while writing a sentence. His speech was mildly slurred; comprehension, repetition, and fluency were normal.

Cranial nerve function:
Visual acuity OD 20/30 OS 20/40 (corrected)
Fundus Normal, no apparent papilledema
Pupils 3 mm,, regular, normal reaction
EOMs The EOMs were full; pursuit & saccades were normal.
V Normal, jaw jerk was brisk.
VII Left central facial weakness
VIII-XII Normal

Motor examination:
There was mild generalized wasting, especially in the hands & feet. Tone was mildly spastic in all extremities, left more than the right.

Reflexes:
Jaw jerk was positive; Hoffmans and crossed adductors positive bilaterally. Glabella, snout & palmo-mental reflexes were negative. The biceps, triceps, brachioradialis, knee, and ankle reflexes were 2+ on the right and 3+ on the left.

Sensory Examination:
Abnormal graphesthesia, stereognosis, and extinction in the left hand.
Light touch over the entire face was abnormal.
Pin & touch perception was decreased on the left side of the body.
Vibration was decreased in the toes; proprioception was normal.


Cerebellar testing:
Finger-to-nose and heel-to-shin were done slowly, but not with prominent ataxia. Rapid alternating movements were slow in the left hand.

Gait:
The patient was barely able to take a few steps, and only with support. His legs moved stiffly, exhibiting circumduction bilaterally, left more than right. Heel walking was more difficult than toe walking. Tandem-walking was abnormal, Romberg was negative, and he was unable to walk on his toes or his heels.

What tests would you order?
What is your diagnosis?

[Surgeon]

I would suggest from the history and exam that the following may be possible:
1. Motor Neuron Disease -suggested by progressive weakness and gait abnormalities; rule out with EMG and muscle biopsy.
2. Mutliple Sclerosis - suggested by both motor and sensory involvement, check for diffuse enhancing lesions on MRI.
3. Infectious - Toxoplasmosis, Cysticercosis (HIV positive?) CHeck for enhancing lesions on MRI.
4. Neoplasm - Diffuse lymphoma or mets to the brain (MRI)

Treatment: Start on high dose steroids and see if there is improvement.

[DrIreland]

You would also want to include a stereotactic brain biopsy in the investigation as initiation on immune suppressants may worsen an infective response, this would rule out a vasculitic, infectious, or neoplastic etiology. The diagnosis is Multiple Sclerosis.

Diagnostic Criteria
The Schumacher committee for MS elaborated 6 items needed to diagnose "clinically definite" multiple sclerosis:

* Objective CNS dysfunction
* Involvement of white-matter structures
* Two or more sites of CNS involvement
* A relapsing-remitting or chronic (more than 6 months) progressive course
* Age 10-50 years at onset
* No better explanation of symptoms as assessed by a competent neurologist

Poser, et al. (1983) modified the criteria, expanding the age of onset to 59 and using data from lab studies, including CSF analysis, evoked potentials, and neuroimaging.

Clinical Features

Cognitive impairment:
Frank dementia is an uncommon feature, occurring in less than 5% of patients. Neuropsychological test results have shown that 35-65% of patients have cognitive impairment.3 Total lesion load, based on MRI, has been found to correlate with neuropsychological testing impairment.5
Visual pathways:
Visual disturbances due to optic neuritis are the most common presentation, usually unilaterally in an acute or a sub-acute form. Other common abnormalities include nystagmus, oscillopsia, and internuclear ophthalmoplegia. In various studies, the visual pathways have been found to be affected in 17-36% of patients at onset.
Sensory pathways:
About 22-45% of patients have sensory symptoms at onset. These reflect spinothalamic, posterior column, or dorsal root entry zone lesions.
Motor pathways:
20 to 43% of patients have motor symptoms at onset, due to corticospinal tract dysfunction. Pyramidal tract dysfunction is often mixed with impairment of the cerebellar pathways, as well as involvement of bladder, bowel, and sexual functions.

Test results:

EMG/Muscle Biopsy - Normal
Brain Biopsy - Inflammatory tissue



MRI -



This has been modified from the original selection on the Baylor College of Medicine, Department of Neurology website.