Neuralgic amyotrophy with hourglass-like constrictions: A case report

Table 1 Results of nerve conduction study

Nerve		Stimulation site	Latency (ms)	Amplitude (mV)	Nerve conduction velocity (m/s)
Motor	Rt radial (EIP recording)	Forearm	2.9	6.1	56.0
		Lateral brachium	6.3	5.9
	Lt radial (EIP recording)	Forearm	2.7	5.6	53.8
		Lateral brachium	6.0	5.0
	Rt musculocutaneous (biceps recording)	Erb’s Pt	5.5	8.7
	Lt musculocutaneous (biceps recording)	Erb’s Pt	5.0	2.0
	Rt axillary (deltoid recording)	Erb’s Pt	3.5	11.2
	Lt axillary (deltoid recording)	Erb’s Pt	3.7	7.0
Sensory	Rt superficial radial	Forearm	3.0	26.1	40.3
	Lt superficial radial	Forearm	2.9	20.8	40.9
	Rt lateral antebrachial cutaneous	Elbow	1.7	18.5	42.0
	Lt lateral antebrachial cutaneous	Elbow	2.1	9.6	33.6
	Rt medial antebrachial cutaneous	Elbow	2.3	17.5	42.9
	Lt medial antebrachial cutaneous	Elbow	2.2	15.8	46.2

Rt: Right; Lt: Left; EIP: Extensor incidis proprius.

Table 2 Results of needle electromyography

Muscle	Insertional activity	Denervation potentials		Polyphasic motor unit action potentials	Interference pattern
		Fibrillation potentials	Positive sharp waves
Lt deltoid	Increased	2+	3+	-	Single unit
Lt biceps brachii	Increased	2+	3+	-	Single unit
Lt brachioradialis	Increased	1+	2+	-	Marked reduced
Lt triceps brachii	Normal	-	-	-	Full
Lt flexor carpi radialis	Normal	-	-	-	Full
Lt extensor digitorum communis	Normal	-	-	-	Full
Lt first dorsal interosseous	Normal	-	-	-	Full
Lt abductor pollicis brevis	Normal	-	-	-	Full
Lt pronator quadratus	Normal	-	-	-	Full
Lt infraspinatus	Increased	2+	3+	-	Single unit
Lt rhomboid major	Increased	1+	2+	-	Marked reduced
Lt serratus anterior	Normal	-	-	-	Full
Lt cervical paraspinalis	Increased	1+	2+

Lt: Left.