Hyperekplexia in a patient with a brainstem vascular anomaly.
OBJECTIVE
To describe a patient with a clinical picture suggestive of idiopathic hyperekplexia (IH), who was later found to harbour a subtle brainstem vascular anomaly.


METHODS
A 35-year-old man, 4 years earlier, developed sudden jumping and falling in response to unexpected sensory stimuli.


RESULTS
Neurological examination was normal. Electromyography showed an excessively large and non-habituating motor startle response. There were no mutations of the alpha1 subunit of the inhibitory glycine receptor which cause hereditary hyperekplexia. Although all these findings were consistent with a diagnosis of IH, a blink reflex study showed an enhanced recovery curve suggestive of a brainstem lesion. A detailed MRI study revealed a subtle vascular anomaly involving the lower brainstem.


CONCLUSIONS
This is the first report of sporadic hyperekplexia related to a brainstem vascular anomaly. Subtle damage to the brainstem should always be excluded in patients with sporadic hyperekplexia, regardless of the coexistence of additional clear-cut neurological symptoms.
Gambardella
A
A
Institute of Neurology, School of Medicine, University of Catanzaro, Italy.
Valentino
P
P
Annesi
G
G
Oliveri
R L
RL
Bono
F
F
Mazzei
R L
RL
Conforti
F L
FL
Aguglia
U
U
Zappia
M
M
Pardatscher
K
K
Quattrone
A
A
D000328:Adult; D001767:Blinking / Q000235:genetics / Q000502:physiology; D001933:Brain Stem / Q000098:blood supply*; D002536:Cerebral Arteries / Q000002:abnormalities*; D004252:DNA Mutational Analysis; D004569:Electroencephalography; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009069:Movement Disorders / Q000175:diagnosis* / Q000235:genetics*; D017354:Point Mutation / Q000235:genetics; D012890:Sleep / Q000502:physiology; D014851:Wakefulness / Q000502:physiology