Neupsy Key

Blinking is one of the most frequent motor actions that humans perform every day. It involves the rapid activation of the orbicularis oculi muscle and relaxation of the levator palpebrae…

Autonomic disturbances are a characteristic feature of certain neurologic disorders; may be a cause of death in others; and sometimes complicate general medical disorders, such as diabetes mellitus. For most…

Visual evoked potentials (VEPs) are massed electrical signals generated by occipital cortical areas 17, 18, and 19 in response to visual stimulation. VEPs differ from the electroencephalogram (EEG) in that…

The term quantitative electromyography (QEMG) refers to a number of different electrodiagnostic techniques and methods of gathering and analyzing data ( Table 12-1 ). No simple definition applies to all…

Invasive recording techniques, in which electrodes are placed on or in the brain to record its activity, are important electrophysiologic tools in the presurgical evaluation and surgical treatment of patients…

H reflexes and F waves are commonly recorded electrophysiologic responses ( Figs. 18-1 , 18-2 , and 18-3 ). H reflexes are reflexes that are produced by afferent conduction in…

Microneurography was developed by Karl-Erik Hagbarth and Åke Vallbo in Uppsala, Sweden in the early 1960s, and the first definitive papers were published in 1968 (on cutaneous and muscle afferents)….

Over the past 30 years there have been few significant changes to the neurophysiologic investigation of patients with suspected neuromuscular disorders. Motor and sensory nerve conduction studies, in combination with…

The electroencephalogram (EEG) is a valuable tool in neurologic diagnosis. However, its value depends on the correct identification of abnormalities so that benign variants and artifacts are not mistaken for…

The term electromyography refers to methods of studying the electrical activity of muscle. Over the years, such methods have come to be recognized as an invaluable aid to the diagnosis…