Radiculopathy
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A 48-year old diabetic dock worker sustains an unwitnessed fall at work. He subsequently reports right leg pain as well as burning involving the anterior thigh. He is seen by the company doctor and treated with anti-inflammatory agents and then physical therapy. Because of failure to respond, he undergoes MRI of the lumbosacral spine which reveals the presence of a mid-size herniated disc at the L5/S1 level compressing the right S1 nerve root. The patient is treated conservatively though requires narcotics for pain relief.
Comment:
The fact that the fall was unwitnessed raises questions whether or not a work injury actually occurred. A herniated disc compressing the right S1 nerve root would cause sciatica and not anterior thigh pain that the patient is complaining of. An EMG and nerve conduction study would be required to explain the presence of the thigh pain, the accompanying numbness of the thigh, and weakness of flexion at the hip, all of which would be uninvolved by a right S1 radiculopathy.
Case Study:
The patient is sent for EMG and nerve conduction studies to Dr. X who the orthopedist believes does a good job. Dr. X reports peripheral neuropathy and S1 radiculopathy. The peripheral neuropathy in this case is likely secondary to the underlying diabetes. However, the finding of the S1 radiculopathy is a bit of a surprise given the patient’s symptoms which do not correlate with the S1 radiculopathy.
The patient goes to surgery and is unchanged. The patient remains disabled. The patient is sent to see Dr. Y by the insurance company. Dr. Y is board-certified in EMG. He finds evidence of weakness of the right thigh flexor and a sensory deficit overlying the right anterior thigh. He reviews the EMG performed by Dr. X. Surprisingly, the report form is a preprinted report form. All patients seeing Dr. X would have the identical lower extremity study performed. Unfortunately on this report form, there is no muscle listed which controls flexion of the hip, the weak muscle in the dock worker which needed to be studied at the time of the first visit.
Comment
The rationale for selection of muscles is explained by the accompanying radiculopathy overview and feature tables and root innervation of upper extremity muscles. In this patient with an L2/3 radiculopathy with weakness of hip flexion and burning over the thigh, muscles which needed to be studied included the iliacus (iliopsoas). Without studying the iliacus or other L2-3 muscles, an incomplete examination would have been performed on this patient.
Case Study:
Repeat EMG is performed revealing the presence of changes within L2 and L3 muscles as well as the neuropathy. A diagnosis of radiculoneuropathy is made. This would be unrelated to any findings seen on the original MRI. One would conclude with a high degree of medical certainty based on the EMG and the clinical presentation that the complaints are as a result of the diabetes. The unwitnessed fall never occurred.
Comment:
For needle EMG to be of value, the following requirements must be met:
1. Sufficient muscles must be studied.
2. Clinically weakened muscles must be studied.
3. Muscles with similar root innervation which are supplied by different peripheral nerves must also be examined.
If the above requirements are not met, the needle EMG would be considered incomplete, and you might have results similar to disastrous results in the case above.
P.S. Because of the surgery, this patient was considered to be totally and permanently disabled. The disability payout in this case was in the seven digits.