Neupsy Key

The structure of the neuromuscular junction explains why it is so powerful. An axonal branch terminates in a branched structure that is laden with mitochondria, synaptic vesicles, and a number…

The presynaptic nerve terminal is the site of synthesis, release, and reuptake of the neurotransmitter acetylcholine (ACh), the chemical responsible for neuromuscular transmission. Acetylcholine is synthesized in the peripheral nerve…

Spinal Muscular Atrophy Type I (Werdnig-Hoffmann Disease). In the healthy newborn infant, the purposeless movements of the extremities are associated with a well-defined muscular tone, despite the lack of coordinated…

Respiratory failure is the cause of death in most patients. Early in the course of the illness, the patient should be warned against the use of respiratory depressants such as…

TREATMENT To date, riluzole is the sole Food and Drug Administration (FDA)-approved drug for the treatment of ALS. Several randomized trials have demonstrated that riluzole prolongs the life of ALS…

DIAGNOSIS In a patient with symptoms of footdrop or an atrophied hand, the diagnosis usually considered is an isolated lesion of a peripheral nerve or nerve root. If such a…

Juvenile monomelic amyotrophy (JMA) is characterized by insidious onset of unilateral or asymmetric muscular atrophy and weakness of the hand and forearm in the absence of sensory or pyramidal signs….

Cognitive dysfunction is present in up to 60% of patients with ALS and can range from mild impairment of word fluency to frontotemporal lobe dementia. This discovery has led to…

The signs and symptoms characteristic of many of these diseases (e.g., PMA, PLS) eventually evolve in most patients to demonstrate mixed upper and lower motor neuron involvement and thus a…

Some muscles are huge. The gluteus maximus has many thousands of muscle fibers essential to walking. Miniscule muscles are designed to produce the slightest movements of the eardrum or the…