A 34-year-old woman presented with a history of paresthesia up to T6.
MRI displayed two T2-bright signals: one occipital and one intraspinal at the T4 level.
Oligoclonal bands were present in the spinal fluid.
The patient was considered at risk to develop MS.
Five weeks after dysesthesia had resolved, a right-sided segmental dystonia developed over 24 hours consisting of flexed posture of the hand, extension and abduction of fingers, with adduction of the thumb, forearm flexion on the arm, and extension of the shoulder.
The contractions sometimes also involved the right side of the face and neck as well as the proximal lower limb (slight hip flexion).
Each episode lasted 15 to 30 seconds. Initially, these contractions occurred rarely, then up to more than 100 times a day within a few days.
Hyperventilation precipitated the attacks during which the patient remained fully conscious without speech difficulties.
These involuntary contractions prevented daily activities.
The only other neurologic finding was a simultaneous mild weakness of right finger extension and abduction.
A brain MRI performed 3 days after onset of the paroxysmal dystonia and 4 weeks after the first brain MRI showed a large T2-bright lesion that was not visible on the initial MRI scan.
This left-sided T2-bright signal involved the lateral part of the thalamus, the posterior limb of the internal capsule, and the internal part of the lenticular nucleus (figure, A).
Postgadolinium, T1-weighted sequences showed enhancement restricted to the posterior limb of the internal capsule and the internal part of the lenticular nucleus (figure, B), reflecting the active breakdown of the blood–brain barrier.
One gram methylprednisolone every day for 3 days did not improve the severity and frequency of the dystonic movements, although acetazolamide 250 mg BID stopped it within a few hours.
Acetazolamide treatment was discontinued after 1 month.
Symptoms did not recur.
Figure. (A) Brain MRI, T2-weighted image on an axial plane (5-mm-thick), performed a few days after onset of the paroxysmal dystonia showing a well-differentiated, rounded bright signal involving the lateral part of the thalamus, the posterior limb of the internal capsule, and the internal part of the lenticular nucleus.
Figure. (B) Postgadolinium-enhanced,
T1-weighted sequences shows enhancement restricted to the posterior limb
of the internal capsule and the internal part of the lenticular nucleus.
© 2001 American Academy of Neurology