Hyperreflexia

Hyperactive deep tendon reflexes area sign of upper motor neuron lesion. They are also commonly seen in normal but tense people. Proper technique of reflexes examination and experience play a major role in eliciting and categorizing deep tendon reflexes. Clonus is the highest degree of hyperreflexia. The most important neuromuscular disease associated with hyperreflexia is ALS due to degeneration of the cortical motor neurons. Diagnostic difficulty occurs when hyperreflexia and spasticity are the only findings. In these cases, PLS, HSP, and other causes of myelopathies should be entertained. Jaw clonus often indicates a lesion above the midpontine level. When hyperreflexia is found, it is wise to look for other features of upper motor neuron dysfunction such as positive Babiniski signs and hypertonia.