Movement Disorders Vol. 5 , No. 2, 1990, pp. 167-169 0 1990 Movement Disorder Society
Brief Report
Exaggerated Startle Reflexes in an Elderly Woman J. G . Colebatch, G . Barrett, and A. J. Lees National Hospitals for Nervous Diseases, London, England
Summary: A 76-year-old woman with a 5-year history of excessive startle is reported. Electrophysiological recordings were made of muscle activation after acoustic and proprioceptive stimulation. The findings are discussed in relation to current knowledge of the startle reflex and classification of startle syndromes. It is concluded that this patient is best regarded as having a pathological exaggeration of the normal startle reflex rather than other causes of stimulus-sensitive muscle jerks. Key Words: Startle reflexElectromyography.
Full blood count, free thyroxine, liver function tests, serum calcium and magnesium levels were normal. Computerised axial tomography and magnetic resonance imaging of the brain were normal. A resting electroencephalogram showed no abnormality and it was noted that there were no abnormal discharges associated with evoked startle. Visual evoked and brainstem auditory evoked potentials were normal. Somatosensory evoked potentials after median nerve stimulation at the wrist were large [N,,-P,, peak-to-peak amplitudes were 14.8 (right) and 17.6 (left) pV] but were not considered abnormal (normal range
Brief Report
Exaggerated Startle Reflexes in an Elderly Woman J. G . Colebatch, G . Barrett, and A. J. Lees National Hospitals for Nervous Diseases, London, England
Summary: A 76-year-old woman with a 5-year history of excessive startle is reported. Electrophysiological recordings were made of muscle activation after acoustic and proprioceptive stimulation. The findings are discussed in relation to current knowledge of the startle reflex and classification of startle syndromes. It is concluded that this patient is best regarded as having a pathological exaggeration of the normal startle reflex rather than other causes of stimulus-sensitive muscle jerks. Key Words: Startle reflexElectromyography.
Full blood count, free thyroxine, liver function tests, serum calcium and magnesium levels were normal. Computerised axial tomography and magnetic resonance imaging of the brain were normal. A resting electroencephalogram showed no abnormality and it was noted that there were no abnormal discharges associated with evoked startle. Visual evoked and brainstem auditory evoked potentials were normal. Somatosensory evoked potentials after median nerve stimulation at the wrist were large [N,,-P,, peak-to-peak amplitudes were 14.8 (right) and 17.6 (left) pV] but were not considered abnormal (normal range
