Neurophysiological Testing

Accurate diagnosis of patients with inhalant use disorders may require a variety of methods, including psychiatric history and mental status examination, physical examination and laboratory testing, neuropsychological testing, and neurophysiological testing. 

The primary approach currently used to detect and characterize potential neurotoxicants involves the use of animal models, particularly rodents. Behavioral and neurophysiological tests, often similar to the ones used in humans, are typically administered. The sensitivity of these measures to neurotoxicant exposure is widely accepted. Although it is often not possible to test toxicant effects on some higher behavioral functions in animals (e.g., verbal ability, cognitive flexibility), there are other neurobehavioral outcomes such as memory loss, motivational defects, somatosensory deficits, and motor dysfunction that can be successfully modeled in rodents. These behaviors are based on the ability of the nervous system to integrate multiple inputs and outputs, thus they cannot be modeled adequately in vitro. Although the bulk of neurotoxicity data has been collected in rodents, birds and primates are also used to model human behavioral outcomes. 

In conclusion, the subcommittee s review of the literature suggests that the use of this test to assess peripheral nerve function among persons exposed to neurotoxicants is reasonable if corroborated with data from conventional validated neurophysiological tests. However, performance on this test cannot be relied upon by itself to establish exposure levels for neurotoxicants. 

Sensory examination should include touch, pinprick, pressure, cold, heat, and vibration assessment [5j. Responses are graded as normal, decreased, or increased to determine whether negative or positive sensory phenomena are involved. The stimulus-evoked (positive) pain types are classified as dysesthetic, hyper-algesic, or allodynic, and according to the dynamic or static character of the. stimulus [6,7]. A m ore sophisticated neurophysiological test is the quantitative... 

Table 2 Comparison of results from neurophysiological testing for the subsample of children (n = 76) at ages 6 (1982) and 9 (1985)...

As for the outcome of neurophysiological testing (Table 4) fewer significant associations with lead exposure were observed for sensory nerve conduction velocities (NCV) of peripheral nerves as opposed to measures of central visual processing taken from characteristics of the visual evoked potential (pattern reversal). Generally speaking VEP latencies decreased with increasing lead... 

Hale M, Al-Seffar J (2008) Preliminary report on aerotoxic syndrome (AS) and the need for diagnostic neurophysiological tests. JAssoc Neurophysiol Sci 2 107-118 Holcomb LC (1988) Impact of environmental tobacco smoke on airline cabin air quality. Environ Tech. Lett 3, 11 June 1988... 

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