Sign of the day
DOI’S SIGN
This is specific to
LAMBERT EATON MYASTHENIC SYNDROME ,
an autoimmune disorder affecting neuromuscular junction.
THE MANEUVER.
Deep tendon reflexes ( knee or Ankle) are initially assessed & found to be absent or markedly diminished.
The Pt is then asked to maximally contract the relevant muscle for a short period ( Vigorously pushing against resistance)
RESULT
immediately following this maximal contraction, repeating the reflex test will cause the previously absent deep tendon reflexes to successfully appear or significantly strengthen.
THE MECHANISM
The temporary surge in calcium at the nerve terminal during sustained contraction overcomes the synaptic block characteristic of LAMBERT EATON MYASTHENIC SYNDROME.
60% of LEMS is associated with malignancy, most commonly SMALL CELL CARCINOMA OF LUNG
Nerve conduction study shows INCREMENTAL RESPONSE when a nerve repeatedly stimulated.
Blood test-to detect Anti VGCC antibodies
Named after Edward H Lambert & Lee Eaton from Mayo clinic who first described in 1956.
Dr. Prabhakar K
Prof of Medicine
SDUMC, kolar.