RESEARCH: PLS--Abnormal blink reflex

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Blink reflex in primary lateral sclerosis.

Podikoglou DG, Avramidis TG, Papadimitriou AL.

Department of Neurology, Red Cross Hospital, Athens,

Greece. Department of Neurology, University of

Thessaly, Thessaly, Greece.

OBJECTIVE: To investigate the underlying

pathophysiology of primary lateral sclerosis (PLS)

regarding possible changes in blink reflex (BR)

circuit. METHODS: BR was studied in 10 patients in

whom diagnosis of PLS was established by comparing

them to two control groups: ten patients with

amyotrophic lateral sclerosis (ALS) and 30 healthy

volunteers. All patients were followed up annually for

a 5 year period. A typical evoked potential study of

the BR was employed. RESULTS: Significantly lower

values of R(2) and R(2)' amplitude were found both in

the PLS and ALS groups compared with the healthy

control group. All these differences were highly

significant (p<0.001). R(1) amplitude and latency, as

well as R(2) and R(2)' latencies, were normal in all

patients. Annually recorded follow up data revealed no

significant changes in BR values for PLS patients. In

contrast, for ALS patients, BR progressively

disappeared following clinical impairment.

CONCLUSIONS: The study suggests that BR is abnormal in

PLS. It also adds some clues regarding PLS

pathophysiology and can be helpful as a marker of ALS

progression.

SOURCE: J Neurol Neurosurg Psychiatry. 2004

Jul;75(7):1064-5.

http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve & db=PubMed & list_uids=1\

5201377 & dopt=Abstract