A 40 Year Old Woman presents With Unsteady Gait And Recurrent Falls.

A 40-year-old woman presented with a five-day history of recurrent falls and an unsteady gait. She had a past history of a stroke causing a right-sided hemiparesis, which resolved spontaneously after a few days. The patient underwent intensive investigation following presentation with the stroke including carotid Doppler studies, transoesophageal echocardiography and CT scan
of the brain, which were normal.
The Ct Scan is shown below which is normal:

On examination she had a broad-based gait. There was evidence of dysdiadochokinesia in both upper limbs and abnormal heel–shin testing. The lower limb reflexes were brisk and the plantar response was extensor. The heart rate was 80 beats/min and regular. The blood pressure was 130/90 mmHg. Both heart sounds were normal.

Question :
What is the most probable diagnosis? ( Chose the one best from the options below)
a. Systemic lupus erythematosus with cerebralinvolvement.
b. Multiple sclerosis.
c. Multiple paradoxical emboli.
d. Friedreich’s ataxia.
e. Multiple cerebral metastases.


Answer:
b. Multiple sclerosis.

Explanation:

The patient has had a previous right hemiparesis and now presents with ataxia. Neurological examination reveals findings consistent with a cerebellar syndrome and bilateral pyramidal tract involvement.
The differential diagnosis of cerebellar and pyramidal tract involvement includes:

• multiple sclerosis, 
• subacute combined degeneration of the spinal cord,
•  Friedreich’s ataxia, 
• multiple cerebral metastases and 
• multiple cerebral infarcts.

The most probable diagnosis is multiple sclerosis, a demyelinating disorder characterized by involvement of the optic tracts, pyramidal tracts, cerebellar peduncle and the posterior columns of the spinal cord.
The normal CT scan of the brain and carotid Doppler studies are against the diagnosis of multiple cerebral metastases and infarctions.
A normal transoesophageal echocardiogram is against the diagnosis of paradoxical emboli.
Whereas SLE may manifest with multiple neurological manifestations, the patient does not have any other manifestations of a multi-system disorder. With specific reference to SLE there is no history of arthralgia, myalgia or a rash.
Whilst Friedreich’s ataxia may be associated with pyramidal tract and cerebellar involvement, the condition usually presents at a much younger age and is associated with progressive neurological deterioration. The condition also affects the dorsal root ganglia, which causes absent peripheral reflexes.