Hereditary neuropathy with liability to pressure palsies and amyotrophic lateral sclerosis

Abstract

A 56-year-old male with recurrent painless focal neuropathies and a family history of peripheral neuropathy of unknown etiology presented with progressively worsening of impaired sensations and weakness in his lower extremities. His initial electrodiagnostic evaluation was suggestive of severe sensory and motor peripheral polyneuropathy. The genetic testing was performed for familial causes of peripheral neuropathy as there was a family history of peripheral neuropathy of unknown etiology. The patient was found to have 1.5-Mb deletion in the PMP22 gene which was confirmatory of hereditary neuropathy with liability to pressure palsies (HNPP). He developed progressive upper and lower extremity weakness, bulbar dysfunction and widespread fasciculations during the course of his illness. He was subsequently diagnosed with amyotrophic lateral sclerosis (ALS). This is the second reported case of HNPP associated with ALS. We discuss significant clinical and electrodiagnostic findings of this interesting case.

Appendix

EMG summary table

	Spontaneous					MUAP			Rec
Muscle	IA	Fib	PSW	Fasc	Poly	Amp	Dur	PPP	Pattern
R. APB	N	1+	NONE	1+	NONE	1+	1+	1+	↓
R. FDI	N	1+	1+	NONE	NONE	1+	1+	1+	↓
R. FCR	N	1+	NONE	2+	1+	1+	1+	1+	↓
R. Biceps	N	NONE	NONE	2+	1+	N	N	N	N
R. Deltoid	N	NONE	NONE	2+	1+	N	N	N	N
R. Thor. PSP	N	1+	1+	1+	NONE	N	N	N	N
R. Gastroc MH.	N	2+	2+	NONE	NONE	↓	1+	1+	↓
R. Gastroc LH	N	1+	2+	1+	NONE	N	1+	1+	↓
R. Biceps SH	N	1+	NONE	1+	NONE	N	N	1+	↓
L. Gastroc MH	N	1+	2+	1+	NONE	↑	1+	1+	N
L. Gastroc LH	N	1+	2+	2+	NONE	↑	1+	1+	↓
L. Biceps SH	N	NONE	NONE	1+	NONE	N	1+	1+	↓
R. Tibialis A	N	1+	1+	NONE	1+	N	1+	N	N
R. Peroneous L	N	1+	2+	NONE	NONE	N	N	1+	↓
R. EHL	N	1+	1+	1+	NONE	N	N	1+	N
R. Rectus F	N	1+	2+	1+	1+	N	1+	N	N
R. Adductor L	N	NONE	NONE	NONE	NONE	N	N	N	N
R. Vastus M	N	NONE	1+	1+	NONE	↑	1+	N	N
R. Ileopsoas	N	NONE	NONE	NONE	NONE	N	N	N	N
R. Glut Medius	N	NONE	1+	NONE	NONE	↑	1+	1+	↓
R. Lumb Parasp	N	NONE	NONE	1+	NONE	N	1+	1+	N
L Tibialis A	N	NONE	1+	NONE	1+	N	1+	N	N
L Peroneous L	N	1+	1+	NONE	NONE	↑	N	N	N
L EHL	N	1+	1+	1+	NONE	↑	1+	N	N
L Rectus Fem	N	1+	1+	1+	1+	↑	1+	1+	↓
L Adductor L	N	NONE	NONE	1+	NONE	N	N	N	N
L Iliopsoas	N	NONE	NONE	1+	NONE	N	N	N	N
L Glut Med	N	1+	NONE	1+	NONE	↑	N	1+	↓
L Lumb Paraspinals	N	1+	1+	1+	NONE	↑	1+	1+	N

Sensory NCS	Site	Record	Peak latency (ms)	Peak Amplitude (μV)	Distance (cm)	Velocity (m/s)	Temp (cent)
L Median	Wrist	II	7.35	4.1	14	22	32
R Ulnar	Wrist	V	4.15	7.6	14	43	33
R Radial	Forearm	I	4.10	7.3	10	44	33
R Sup Peroneal	Leg	Ankle	No response
R Medial Plantar	Leg	Sole	No response
L Medial Plantar	Leg	Sole	No response
L Sup Peroneal	Leg	Ankle	No response
R Median	Wrist	II	No response
R Median	Wrist	Palmer	No response
R Sural	Leg	Lateral malleolus	No response
L Sural	Leg	Lateral malleolus	No response

Motor NCS	Site	Record	Latency (ms)	Amp (1–2 mV)	Distance (cm)	Velocity (m/s)
R Median	1. Wrist	APB	9.65	5.4	8
	2. Elbow		15.90	4.8	24	38
L Median	1. Wrist	APB	8.05	5.7	8
	2. Elbow		12.90	5.1	22	45
R Ulnar	1. Wrist	ADM	3.70	6.0	8
	2. B.Elbow		8.15	4.7	23.5	53
	3. A.Elbow		11.35	4.2	13	41
R Peroneal	1. Ankle	EDB	9.0	0.3	37	26
	2. F.head		23.3	0.3	10	31
	3. Knee		26.5	0.3
L Peroneal	1. Ankle	EDB	6.6	0.4	34	33
	2. F.head		17.0	0.4	10	36
	3. Knee		19.8	0.3
R Tibial	1. Ankle	AH	7.8	0.3	46.5	35
	2. Knee		21.2	0.4
L Tibial	1. Ankle	AH	8.2	0.4	44	29
	2. Knee		23.3	0.3

	Latency (ms)
F Wave
R Ulnar-ADM	39.3
R Median-APB	43.8
L Median-APB	46.5
R Peroneal	83.7
L Peroneal	71.8
H Wave
R Tibial	50.6
L Tibial	48.2