Consensus criteria for the diagnosis of partial conduction block
. Muscle Nerve 1999;8:225-229.
The spectrum of distal conduction block
and axonal degeneration.
In the early stages, a partial conduction block
may cause no symptoms but can be detected by an electrocardiogram (EKG), a painless test of how the heart is beating.
documented transient improvement in MS symptoms in patients treated with the use of hyperventilation, sodium bicarbonate, and EDTA. These treatments are thought to work by decreasing calcium ion concentrations in the area of the nerve fibers, possibly opposing the conduction block
caused by the temperature increase.[5,32]
Twelve cases (63.2%) showed conduction blocks
, including right bundle branch block (RBBB) in three cases, complete atrioventricular block (AVB) in three cases, complete AVB with RBBB in three cases, left anterior fascicular block (LAFB) in one case, RBBB with LAFB in one case, and Mobitz type II 2[sup]nd degree AVB with RBBB in one case.
Although the number of extremities in which latency change with focal conduction block
was detected was 30, the number of extremities in which only conduction block
was found was 27 (Table 4).
The presence of a diminished amplitude at or proximally to the site of lesion, without TD is defined as conduction block
(Figures 5 and 6).
(7) According to an ad hoc subcommittee of the American Academy of Neurology, 3 of the following 4 criteria for demyelination should be present on nerve conduction studies to make the diagnosis of CIDP: partial motor-nerve conduction block
, reduced motor-nerve conduction velocity, prolonged distal motor latencies, and prolonged F-wave latencies.
Neurapraxis (nerve "shock") results simply in a conduction block
along the neurite.
Nerve conduction studies shows reduced conduction velocity with conduction block
, accompanied with increased distal latency.
Following the acute inflammatory response, the resultant fibrosis and scarring leads to an electrical conduction block
and reentry circuits predisposing patients to life-threatening ventricular arrhythmias.
Practice parameters for electrophysiological diagnostic criteria of ulnar neuropathy at the elbow:[sup] (1) the nerve conduction time of each segment was mean + 2 standard deviations (SDs) longer than the same segment in the healthy group; (2) conduction block
was found in proximal segment compared with the successive distal segment that CMAP was reduced by 20% or more and duration was increased by 10% or less.