An Electromyographer's Look at Hereditary Neuropathy with Liability to Pressure Palsy

Hereditary neuropathy with liability to pressure palsy (HNPP) or tomaculous neuropathy shares a molecular genetic relationship with Charcot Marie Tooth Disease type I (CMTI) in an autosomal dominant manner1.  Most cases of CMT1A are caused by the duplication of 1.5mb in chromosome 17p11.2, while upwards of 85% of all HNPP cases are a result of the inverse of this mutation1. Mutations within the PMP-22 gene cab also cause HNPP1, 2, 3.  The term “tomaculous” is derived from the focal globular thickening of the myelin sheath that resembles sausages, which are revealed during nerve biopsies1,3. The purpose of this case study…

Taking the Mystery Out of an EMG/NCS Report – Part 2

In Part One of this article, I discussed the basics of nerve conduction studies and waveform analysis. In Part Two, I will cover principles of needle electromyography (EMG), specific diseases and injuries that relate to hand therapy, and how EMG/NCS findings relate to outcomes for certain injuries and surgeries of the upper extremities.   The needle EMG examination is performed “on the fly” requiring in-depth knowledge of nerve and muscle physiology and how they relate to both normal and abnormal electrical activity in the muscle. While the muscle fibers belonging to a single motor unit can be distributed over 5-10 mm or more, the needle records…

If It Quacks Like a Duck…Is it Always a Duck? EMG/NCS Findings in Patients with “Carpal Tunnel” Symptoms

You’ve probably heard the expression, “measure twice, cut once.”  Nowhere is that adage truer than in the field of medicine. Electromyography and nerve conduction studies (EMG/NCS) are part of the measurement process which helps physicians provide the most accurate diagnosis and appropriate treatment for symptoms which can sometimes be rather vague. Take carpal tunnel syndrome (CTS), for example.  This condition involves dysfunction of the median nerve at the wrist, and it usually manifests as numbness, tingling, and pain in the affected hand.  But although carpal tunnel syndrome is the most common compression neuropathy, nerve damage in many other areas can…

Suprascapular Nerve Compromise

Nerve conduction studies (NCS) and electromyography (ECS) help illuminate confusing neurologic cases and can pinpoint the origin of a problem. In this patient’s case it so happened to be from the suprascapular nerve. Going to a bar with a friend or loved one does not always go wrong but for this 42-year old man things got messy when he was assaulted while getting a drink 3 years ago with his wife. After the traumatic ordeal he ended up bruised, bleeding, and with a broken right scapula. He was evaluated at the emergency room and sent on his way. It was…

Sinus Tarsi Research

The providers at EMG Solutions are always striving to remain at the top of their field while providing ways to help the discipline as a whole.  The following was original research performed by one of EMG Solutions’ own providers.  This research was presented as a poster presentation at the American Physical Therapy Association’s (APTA) Combined Sections Meeting (CSM). Surface Anatomy and Nerve Innervation of the Sinus Tarsi:  Cadaver Study Hao (Howe) Liu, *Steve Forbush, *Wen Wang, *Mark Simmons Physical Therapy Department of University of North Texas Health Science Center, Fort Worth, TX *Physical Therapy Department of University of Central Arkansas,…