Reflex epilepsy in demyelinating encephalopathy – a case report

An 11 year old patient with right-sided spastic cerebral palsy and complex partial epilepsy due to demyelinating encephalopathy reported of sudden „jerks“ in his right thigh. When the patient stumbled unexpectedly with this paretic leg, myoclonic jerks occurred, lasting only a few seconds. However, the jerks often led to the patient falling, his right leg feeling stiff and useless for several minutes afterwards. These episodes happened several times each day without any alteration of the patient's consciousness.

Diagnostics: In the EEG sparse spike -waves over the left fronto-central region were found. A cerebral MRI-Scan showed bilateral periventricular enhancements and atrophy of the left hemisphere, both unchanged compared to former imaging. No pathology was found in MRI-Scans of the spinal cord and both thighs. Motor nerve conduction velocity of both legs was normal.

Simultaneous video- and eeg-recording of an episode with myocloni of the right rectus femoris muscle was successful when the patient was unexpectedly pushed forward by the examiner. During this episode a series of spike-waves over the left fronto-central region was registered. This enabled the diagnosis of reflex epilepsy. After a change in his anticonvulsive treatment the patient became seizure-free.

Discussion: In the case presented focal seizures were triggered by reflective muscle contraction against gravity. We assume that the underlying demyelinating encephalopathy made the patient liable to focal seizures, especially as lesions were found in the precentral motor cortex.