title: The H or F wave latencies in medial gastrocnemius in the electrodiagnostic study of sciatica patients with suspected S1 radiculopathy.
abstract: The aim of this study was to test H or F wave latencies of medial head of gastrocnemius muscle for electrodiagnostic evaluation of patients with suspected S1 radiculopathy with or without additional L5 radiculopathy. A group of 97 patients (34 female and 63 male), aged 20-60 (average 44 years), with clinically suspected unilateral radiculopathy were studied. Needle EMG of medial gastrocnemius muscle was supplemented by H or F wave latencies measurement bilaterally by percutaneous stimulation of tibial nerve in cubital fossa. EMG abnormalities indicating S1 radiculopathy were followed by H or F wave latencies abnormality in 63% of patients. The rest of 37% of patients of these group showed mild EMG abnormalities followed by normal H or F wave. Normal EMG finding was followed by normal H or F wave. Normal EMG finding was followed by normal H or F wave in 64% of patients. Increased latency of H or F wave without EMG abnormalities in gastrocnemius muscle was present in 36% of patients. The results of this study have proved that measurements of H of F latencies provide the objective evidence of S1 radiculopathy, presenting with the unilateral increase of latency or the absence of response. Abnormal H response latencies without EMG abnormality confirm the condition of sensory root affection only. Mild radicular affection in S1 distribution presented from early beginning or following recovery, was accompanied by normal H or F response, and therefore this test has prognostic value for the course of disorder.
authors.affiliation: Institute for Physical Medicine, Rehabilitation and Rheumatology, General Hospital Sveti Duh, Zagreb.
authors.forename: A
authors.initials: A
authors.lastname: Bobinac-Georgijevski
authors.forename: B
authors.initials: B
authors.lastname: Sokolović-Matejcić
authors.forename: M
authors.initials: M
authors.lastname: Graberski
mesh_terms: D000328:Adult; D004576:Electromyography; D005260:Female; D006181:H-Reflex / Q000502:physiology*; D006801:Humans; D007866:Leg; D008297:Male; D008875:Middle Aged; D009046:Motor Neurons / Q000502:physiology*; D009132:Muscles / Q000294:innervation*; D009408:Nerve Compression Syndromes / Q000175:diagnosis; D011930:Reaction Time; D012585:Sciatica / Q000503:physiopathology*; D013126:Spinal Nerve Roots / Q000503:physiopathology