ELECTROPHYSIOLOGICAL DIAGNOSIS IN A CASE OF GLASS CUT INJURY THAT NEEDS LOGICAL THINKING WITH THOROUGH KNOWLEDGE OF ANATOMY

We come across a wide variety of cases in our routine OPD of a general hospital. Many a times a lot of cases need a logical thinking and application of certain techniques which probably are not described as gold standard protocols but we know that applying these can only lead us to the desired direction.
Few days back I came across one such case. It was easy to conclude but definitely needed experience and logical thinking and insight into anatomy.

 INTRODUCTION OF THE CASE
A male patient with glass cut injury over (rt) palm over first and second metacarpel region. Patient referred for EMG NCV studies by Plastic surgeon who wanted us to detect the exact site and extent of lesion.

CLINICAL EXAMINATION IN BRIEF

The scar on examination was adherent to the underlying structures especially entrapping the flexor tendon of index finger. Clinically minimal sensations present over index finger, minimal hypoaesthesia over middle finger. Normal sensations over thumb and ring fingers.

Patient was apprehensive to perform finger movements due to pain.

ELECTRODIAGNOSIS

Now we will try to logically appraise the rationale of each and every electrodiagnostic test performed with its interpretation

After the clinical assessment, NCV studies were begun.

• Motor Nerve Conduction Velocities both Median and Ulnar nerves were within normal limits with normal distal motor latencies and Compound motor action potential (CMAP) amplitudes.
• Latencies and amplitudes were bilaterally symmetrical and comparable. 
• This suggest that the scar did not affect the motor component of (rt) Median nerve. 

Above tables show many numbers with the titles which may sound different than the textbook ones and would for sure keep someone thinking as to what happened. 

• Distal Sensory latencies and amplitudes both Ulnar nerves were bilaterally symmetrical and comparable which suggested that sensory component of Ulnar nerve was not involved.

Traditional Orthodromic Median Sensory Conduction involves stimulating from Index finger and recording from wrist. 

• On the (rt) side, Sensory nerve action potential (SNAP) could not be elicited. This suggested that there was affection of  Sensory branch of Median nerve on the right side.

Traditional viewpoint would confirm Median nerve injury and would interprete and report the same. But is this enough when we are talking about exact location and extent of injury?

To still go into the depth of the extent of injury, we need to re-evaluate the scar and once again understand the branching of the digital sensory branches of Median nerve

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Looking to above two images the first one showing the branching pattern of the digital branch of Median nerve and the second one showing the site of scar. If we correlate the two, branch 1 going to the thumb would be spared. Branch 2 and 3 three going to index finger would be affected and that was the reason we could not elicit SNAP for Median nerve performed as a traditional technique. But the same Median nerve supplies Middle, ring and lateral half of ring finger as well as branch 4,5,6 in the figure showing nerve branching.

That is the need of today to think out of the box and perform SNCV of digital branches of Median nerve for thumb, middle and ring finger.

We could elicit SNAP for thumb, middle and ring finger for Median nerve. We performed Orthodromic technique with ring electrodes stimulating and surface electrodes placed on wrist recording.

• Distal sensory latencies of (rt) Median nerve for thumb, Middle and ring finger was nearly same.
• SNAP amplitude for middle finger was approximately 50% less than that of thumb and ring finger, though it was within normal limits.

Correlating this with the shape and location of the scar, probably branch number 2,3 and 4 would have been injured due to trauma.

This clinical and electrophysiological arguement was digestible to give a conclusion that there was affection of sensory branch only of the index finger and partial affection of the branch to middle finger.

Yet, as a protocol and to be confirmed that there was no motor involvement even to the minimal extent, EMG study was performed for two muscles, one muscle proximal to the scar Flexor Pollicis Brevis and one muscle distal to the scar 2nd Lumbrical

Though FPB has dual innervation, if Median nerve was denervated at the site of scar, it would definitely give signs of denervation like Fibrillation Potentials or Polyphasic Motorunit action Potentials.

Looking to the table, EMG study of both the muscles tested was normal once again proving with final confirmation that there was no motor involvement. Hence this case can be concluded as

The case looks very simple on first look. But frankly talking about interpreting it electrophysiologically, majority of electrophysiologist would stop at absence of SNAP with traditional technique and interpreting as Median nerve injury at the level of scar. The precision of interpretation of exactly saying it to be only for the branch of Median nerve for Index finger may not have any SO-CALLED RESEARCH EVIDENCE OR TEXT BOOK DOCUMENTATION. Nor does the technique employed to conclude the same has RESEARCH EVIDENCE. BUT THIS DEFINITELY HAS A CLINICAL CORRELATION WHICH IS PROBABLY MORE IMPORTANT THAN ANY TEXTBOOK, JOURNAL OR RESEARCH SAYING BECAUSE AFTER ALL MEDICAL SCIENCE IS FOR THE BETTERMENT OF THE  PATIENT  NOT FOR MERE DOCUMENTATION.

NCV STUDIES IN A ROUTINE PHYSIOTHERAPY CLINIC - OUT OF THE BOX THINKING

Many a times in our clinics we come across patients who often say that they are not better with pain inspite of a lot of hard work by us. We as a Physiotherapist would have tried hard with all possible electrotherapy modalities and manual therapy. We would have then thought and rethought our assessment. And after all the trials we would have jumped into conclusion that the patient presents with a psychosomatic ailment. This is because it is very easy to give this conclusion. Admist all these assessments and treatment plans we fail to think that there can be something else which we probably have missed out. Lets discuss

A patient with Low back pain with Lower limb radiculopathy coming to a Physiotherapy management. We would have tried Electrotherapy, Manualtherapy, Neurodynamics for quite sometime. Still we are not able to help the patient out with lower limbs radicular symptoms.WHAT TO DO?

I WOULD SUGGEST OUT OF THE BOX THINKING -  Can any one have a faintest of idea that these patients can have some form of Neuropathy or Tarsal Tunnel Syndrome also????? Why not????? Same symptoms....Lowerlimbs paraesthesia, sensory affection, at times motor weakness. These are the patients who may have reached middle age, may be diabetic. Vitamin B12 deficiency is not  unknown now a days. With so many known factors one of the differential diagnosis for such cases can be Neuropathy. At times patient's footwear, foot posture and alignment can be at fault which may be responsible for symptoms probably Tarsal Tunnel Syndrome. But since MRI confirmed Spinal Root compression, patient was referred to us for Radiculopathy. We Physiotherapists kept on following the same protocol as referred .MRI is a sensitive test which gives anatomical lesion. It is not specific. Now instead if we had a EMG NCV instrument in our clinic, we could have performed atleast a NCV study and reconfirmed. In radiculopathy, NCV studies are usually normal and in Neuropathy they are abnormal and in Tarsal Tunnel Syndrome only Tibial Nerve abnormal. Just performing them dont need us to interprete. This is just a screening tool for a physiotherapist. But this indeed can help him and entire management changes. What say isnt it?????Discussion on this is unending. Lot to convey lot of information to share. May be some other time.

ANOTHER SCENARIO.......

A patient with lateral epicondylitis. Patient coming to a Physiotherapist since long. We would have tried Ultrasound, Phonophoresis, Manualtherapy like Mulligan mobilization, Taping, Strengthening exercises etc. Yet the patient would say he is not fine. The pain still persists. We would attribute it to his / her occupation. Would give vocational training, all advises. All in vain. Probably a stage would come where we would tell the patient to start ignoring the pain and continue doing the work. Now if we as a Physiotherapist with offbeat thought process, EMG NCV equipment as a screening tool handy and a good knowledge of anatomy, would quickly screen Radial Nerve to rule out Supinator Tunnel Syndrome wouldnt it work? What do you think? Radial Nerve gets entrapped at the same sight mimicking lateral epicondylitis. So finally we have reached the exact diagnosis. And our patient will be finally happy. Now tell me who proved to be a saviour? NCV study. Isn't it?

Suprascapular nerve palsy often mistaken as Rotator cuff tear, Pronator Teres Syndrome mistaken as Carpal Tunnel Syndrome, L5 Radiculopathy mistaken as Common Peroneal nerve Injury around fibular head and the list here is unending

Often a Physiotherapist thinks he is not certified to perform the test or sign a report. Then why should he buy this equipment. Few think that this is a speciality of a Neurophysiotherapist. But a newer perspective needs to be instilled. Simple NCV studies can help us diagnose certain conditions faster and we dont need to sign a report and give a report for it. We have studied NCV studies in our undergraduate and even Post graduate program. Why hesitate to screen our patient with it? But this can definitely help our patients and in turn help our practice

Why only Neurophysiotherapist? Why not Orthophysiotherapist or a Community therapist? Someone who sees degenerative diseases or even trauma and nerve injuries? Combination of neurology with biomechanics will definitely give best perspective when we consider a patient as a whole. How can we see a brain and nerves separately, bones and muscles separately when after all entire body is one

PHYSIOTHERAPISTS NEED TO SEE SUBJECT WITH A DIFFERENT AND A BROADER PERSPECTIVE. WE KNOW BODY FUNCTIONS AND MECHANICS AND HENCE WE CAN DEFINITELY GIVE A GOOD INSIGHT INTO DIFFERENTIAL DIAGNOSIS. 

ELECTRODIAGNOSIS - WHY NOT BY A PHYSIOTHERAPIST

Working with electrodiagnosis since last 15 years with all ups and downs and professional struggles, the question CAN A PHYSIOTHERAPIST PERFORM ELECTRODIAGNOSTIC TEST? In simple words can a Physiotherapist perform EMG NCV study independently.

There is a continuous debate going on among healthcare professionals whether a physiotherapist can perform EMG/NCV studies independently or not. Many of the consultants not accepting it, many accepting it with conditions and many readily accepting it. But this continuous debating has given so many points to be discussed and questioned even to the specialists. And the question arises WHO WILL BELL THE CAT
It is said even in books that EMG NCV studies just confirm a tentative  diagnosis. It needs a couple of provisional diagnosis and a confirmation of one of them through electrophysiological testing is done. A thorough clinical assessment is mandatory before referring a patient for such test and before performing such test. And these textbook sentences become mere Geeta Shlokas of Bhagvat Geeta of EMG/NCV which are seldom practiced.

A consultant who is often a neurologist is so busy that he hardly has time even to talk to his patient. He who is said to have been certified to perform and interprete this report by so called heredity. When they are so bugged up with so many other commitments, why burden them with so much of electrodiagnosis? Where they have time to spend after doing clinical assessment like muscle charting or even talking and taking proper history of the patient.It is definitely an undoubted fact that he has a better diagnostic skills than a physiotherapist but a physiotherapist too is competent enough to judge the abnormalities and inform his consultant.A physiotherapist is well aware of his/her limitations and would never cross the ethical and moral boundaries.

An electrophysiological diagnosis is different from a neurological diagnosis. If this difference is understood by a consultant, majority of the debate causing issues regarding this matter is solved. For example -  A patient with complaint of tingling/numbness over thumb, index and middle finger with prolonged distal motor latency (at wrist) and reduced CMAP amplitude and normal/reduced Nerve Conduction Velocity of Median nerve and prolonged distal sensory latency for Median nerve. Electrophysiological interpretation can be Median nerve compression at/about wrist which a trained Physiotherapist if performs a study can put. But if a Neurologist performs the study can put diagnosis as Carpal Tunnel Syndrome.With this difference why a Physiotherapist cannot perform EMG NCV study independently if PROPERLY TRAINED AND CERTIFIED?

A physiotherapist assesses a patient thoroughly in terms of tone, muscle charting, voluntary control where needed. He/She spends enough time with the patient. Even the curriculum of the Masters in Physiotherapy has Electrodiagnosis in detail. Then why a debate or why a denial that a Physiotherapist cannot perform this study. A physiotherapist learns the same anatomy, physiology, medicine, pharmacology, neurology, orthopedics that a MBBS student learns. Then why he/she is underestimated when it comes to electrodiagnosis.

RATHER THAN KEEPING THIS TEST AS A HEREDITARY RIGHT OF A DOCTOR OR A NEUROLOGIST, WHY A SEPARATE CERTIFICATION CANNOT BE MADE MANDATORY FOR PERFORMING THIS TEST IRRESPECTIVE OF A DOCTOR OR A PHYSIOTHERAPIST PERFORMING IT.AND A CERTIFIED PHYSIOTHERAPIST TOO CAN PRACTICE IT INDEPENDENTLY , NOT AS A TECHNICIAN.

Radiological investigations like Xrays, MRIs are highly sensitive tests and give accurate anatomical lesions, EMG NCV tests are highly specific tests and give accurate functional lesions. And so as a  tool of convenience it is a very common practice now a days to perform EMG NCV studies in majority of the patients irrespective of forming provisional diagnosis or not. It may be called playing safe in an era of Consumer Protection. And very rightly and sarcastically described by a Doctor in all majority of his prescriptions which went as - CBC, ESR, EMG/NCV

As rightly said by Sir De Luca ,the most influential person in the recent history of EMG and one of the editors of fifth editions of the book MUSCLES ALIVE by Basmajin " Electromyography is a seductive muse because it provides easy access to physiological processes that cause the muscles to generate force, produce movement and accomplish countless functions that allow us to interact with the world around us...to its detriment electromyography is too easy to use and consequently too easy to abuse". Said in 1997, this is proving true in 21st century

CONCEPTS - MISCONCEPTS IN ELECTROTHERAPY

I remember one day I was examining a patient with back pain and trying to test my post graduate student with her logical thought process regarding the pain management. To my shock and surprise, she said that she would not prefer any electrotherapy modality because none of the evidences support them. I was speechless. I did not know how to react. This is a routine discussion amongst Physical therapist regarding the use of Electrotherapy modalities. I am sure majority of us would say since evidences are tricky. Post graduate students must not talk about that in examinations as guided by few seniors to their juniors. But the same seniors will not fail to use multimodality approach in their clinics

courtesy-www.electrotherapy.org

 

In a blind run after evidence based practice, modern therapist fail to understand the concept of clinical expertise and clinical experience based practice. And in India, Electrotherapy still stands as one of the most important treatment option which can keep patient trusting you.

CLINICAL REASONING

By favouring the use of Electrotherapy, I dont favour multimodality approach. I strongly recommend accurate clinical assessment. Identifying the culprit structure and applying the electrotherapy modality accordingly. Each modality has its own specific indications and its specific dosimetry. One may not be inter changeably used with another unless indicated. Therapists make mistake in using them. Absence of proven guidelines is considered guilty for this. But standard textbooks do give clear cut guidelines.The dos and the donts. UNLESS YOU IDENTIFY THE STRUCTURE AT FAULT AND DECIDE THE MODALITY ACCORDINGLY WITH THE ACCURATE DOSE PARAMETERS, ALL MODALITIES WILL BE FELT SAME. As rightly said IGNORANCE IS BLISS

My piece of suggestion, just give THE MODALITY - one modality which can give effect to the target tissue and it will definitely give effects

WHY ARE EVIDENCES LACKING

We have heard Physiotherapists always saying evidences are lacking or controversial regarding the use of electrotherapeutic modalities. And blindly following that we keep on saying not to use. But have we ever thought why is it so that these are clinically so useful, yet why are the evidences controversial ?

1. Our researches have outcome measures as VAS, NRS or some other pain scale or any functional scale. We hardly go for biochemical analysis pre and post modality. Even the developed country researches on electrotherapy lack biochemical analysis. Or there are naive researches with biochemical analysis which as a result will reduce  the level of evidence of that study or make a study less reliable. As a result, we cannot consider the results of that study standard because whatever the outcome measures considered here are patient based which are more or less subjective. In absence of serum or biochemical analysis the objectivity of the study is reduced. As a result studies become controversial
2. Majority of the studies done for Medium and Low frequency currents are done for mechanically induced pain or are done on animals. The chemical changes taking place in such instances are different than those during injury process and during chronic pain cycle where centrally mediated certain unknown pathways come into play. Studies lack in this aspect.
3. Due to strict Insurance and Medico-legal policies and Type I and II skin in Western  population, it becomes risky to apply high frequency modalities like shortwave diathermy or microwave diathermy.These patients are at the risk of burns and skin cancer. Hence researches on this population is lacking. As a result moderate to good level evidences are lacking for high frequency electromagnetic radiation modalities like SWD, MWD etc. Since western countries dont use these modalities, and lack of research there, Indian Physiotherapists blindly follow this citing lack of evidence. Skin type of Indian population is mainly Type III or IV and are at a lesser risk of burns or skin cancer. We at India can definitely do research and establish the reliability of these modalities before using or discarding them. Because in India, even today there is a myth in common people that if you dont give them heating modality, they will not feel better. And so even for placebo, you need to give some modality

I dont say ONLY Electrotherapy works. NOTHING CAN REPLACE GOOD HANDS ON SKILLS AND PROPERLY EXECUTED MANUAL THERAPY. But whatever said and done, electrotherapy stands as an important adjunct to Manual therapy even today in Indian population.

People may feel that it is USELESS TO CONDUCT OR ATTEND SEMINARS ON CLINICAL APPLICATION OF ELECTROTHERAPY. Textbooks can teach theory. BUT IT TAKES CREDENTIALITY, CREDITABILITY AND EXPERIENCE OF SENIOR TEACHERS TO TEACH CLINICAL SCENARIO AND MAKE STUDENTS EXECUTE IT IN THEIR CLINICS. AT TIMES THIS CAN BE PROFESSIONAL UPLIFTMENT OR CAREER GROWTH. ONE NEEDS TO THINK OUT OF THE BOX

EMG-NCV WORKSHOP

Hands on work shop by AMERICAN ACADEMY OF CLINICAL ELECTRODIAGNOSIS coming soon in AHMEDABAD.....RESOURCE PERSON  DR. NEHAL SHAH