Vertical supranuclear gaze palsy in Niemann-Pick type C disease.
Vertical supranuclear gaze palsy (VSGP) is a key clinical feature in patients with Niemann-Pick type C disease (NP-C), a rare, autosomal recessive, neuro-visceral disorder caused by mutations in either the NPC1 or NPC2 gene. VSGP is present in approximately 65 % of the cases and is, with gelastic cataplexy, an important risk indicator for NP-C. VSGP in NP-C is characterized by a paralysis of vertical saccades, especially downward, with the slow vertical eye movement systems (smooth pursuit and the vestibulo-ocular reflex) spared in the early phase of the disease. This dissociation is caused by a selective vulnerability of the neurons in the rostral interstitial nuclei of the medial longitudinal fasciculus (riMLF) in NP-C. Here we discuss VSGP in NP-C and how clinicians can best elicit this sign.
Department of Clinical Neurosciences, Fondazione IRCCS Istituto Neurologico Carlo Besta, via Celoria 11, 20133, Milano, Italy. ettore.salsano@istituto-besta.it
Ettore
E
Salsano
Chizoba
C
Umeh
Alessandra
A
Rufa
Davide
D
Pareyson
David S
DS
Zee
D000818:Animals; D001921:Brain / Q000473:pathology / Q000503:physiopathology; D005133:Eye Movements / Q000502:physiology*; D006801:Humans; D009422:Nervous System Diseases / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology; D052556:Niemann-Pick Disease, Type C / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology; D013494:Supranuclear Palsy, Progressive / Q000175:diagnosis* / Q000453:epidemiology* / Q000503:physiopathology