Hyperekplexia and trismus due to brainstem encephalopathy
- aDepartment of Neurology, bDepartment of Neurophysiology, The Walton Centre for Neurology and Neurosurgery, Rice Lane, Liverpool L9 1AE, UK
- Dr Malcolm J Steiger, The Walton Centre for Neurology and Neurosurgery, Rice Lane, Liverpool L9 1AE, UK. Telephone 0044 151 529 4324; fax 0044 151 525 3857.
- Received 30 May 1997
- Revised 25 November 1997
- Accepted 25 November 1997
Abstract
The brainstem is said to be the generator of pathological startle responses due to reticular reflex myoclonus or hyperekplexia. A patient with facial weakness, nystagmus, and pyramidal tract signs had generalised reflex spasms in response to auditory, visual and tactile stimuli which clinically and neurophysiologically resembled hyperekplexia. The case is unusual because as well as hyperekplexia, the patient’s initial presentation was with an equally rare manifestation of brainstem pathology—brainstem mediated trismus. The causes of brainstem trismus and exaggerated startle responses are discussed with respect to their underlying mechanisms.
