AJND CASE PRESENTATION

CASE SHEET - https://113riyagupta.blogspot.com/2022/09/case-of-51-years-old-man-with-loss-of.html

CASE OF A 51YEARS OLD MALE WITH FOOT DROP.

Case Description 

A 51 years old farmer, a chronic tobacco consumer, presented with swelling of the left foot for 3
years, loss of all sensations in the left foot for 3 years, and a painless ulcer in the sole of the left foot
for 11 months.
He reported having an injury of the left foot 25 years ago, that led to swelling of the left foot,
associated with pain, that subsided on taking medication.
He reported having another injury of the left foot 3 years ago. The X-ray of the left foot revealed a
fracture near the base of the 5th metatarsal. Due to financial constraints, he could not undergo
surgery and continued to take medication for the pain and swelling for 9 months and discontinued
as the swelling did not subside. The patient reported walking with a limp.
The patient also reported of development of a tingling sensation in his left foot followed by
progressive loss of sensation, and inability to wear his left slipper, as it would slip forward. He
complains of difficulty while walking and an inability to do his daily work. The patient initially did not
notice the ulcer in the sole of the left foot, due to loss of all sensations. He has no history of any skin
changes, fever, or hypopigmented patches.
On examination, the patient was conscious, coherent, and oriented to time, place, and person. CNS
examination revealed normal cranial nerve function and no focal neurological defects. Steppage gait
was present. Examination of the movement at the left ankle revealed the absence of dorsiflexion
and eversion and presence of plantar flexion and inversion and a loss of toe extension. The knee jerk
reflex and ankle jerk reflex were present in the left lower limb and the plantar reflex was absent.
On sensory examination, the fine touch, crude touch, pain, temperature, and vibration sensations
were absent below the ankle joint. A palpable and thickened common peroneal nerve was present in
the lateral aspect of the knee joint of the left leg.
Investigations, MRI of the left leg revealed a long segmental fusiform swelling of the tibial nerve
with cystic spaces involving the nerve in the distal 1/3rd of the leg, tarsal tunnel, and proximal part
of the hindfoot with a maximum thickness of 12 mm. A similar lesion is seen in the long segment of
the common peroneal nerve at the level of the knee joint associated with fatty atrophy of the
extensor compartment muscles of the leg in the mid and distal 1/3rd of the leg. Suggestive of
intraneural ganglion of the tibial nerve, Hamartoma of the tibial nerve, or, Nerve sheath tumor of
the tibial nerve.
HRUS examination of the left leg revealed a long segmental focal fusiform enlargement of the distal
sciatic nerve just proximal to the bifurcation in the popliteal fossa 10 mm maximum in diameter.
Enlargement extends into the common peroneal nerve for about 6 cm and also involves a proximal
few 2 cm of the tibial nerve. The extended nerve shows hyperechoic echotexture. Suggestive of a
Nerve sheath tumor.
Motor nerve conduction studies revealed no response in the left tibial nerve and left peroneal nerve
recorded at the Adductor hallucis and Extensor digitorum brevis muscles respectively. Sensory nerve
conduction studies revealed no response in the left superficial peroneal nerve and left sural nerve
below the level of the ankle.
Slit skin smear/ skin biopsy was negative for acid-fast bacilli. Bacterial culture of ulcer exudate
revealed the presence of Klebsiella species. Blood work revealed the presence of hemoglobin of 9.9
gm% (moderate anemia), with microcytic hypochromic anemia.
The diagnosis was left lower limb mononeuropathy with thickened nerves with etiology under
clinical evaluation. Treatment that was given included Gabapentin tablets 100 mg, Multivitamin

supplements and amitriptyline tablets 25mg.

Case Discussion 

“Peripheral neuropathy refers to the many conditions that involve damage to the

the peripheral nervous system, which is a vast communications network that sends signals

between the central nervous system (the brain and spinal cord) and all other parts of the

body.”(1) Neuropathy may involve only one nerve (mononeuropathy) or may affect two or

more nerves in different areas (mononeuropathy multiplex) or involve many or most of the

peripheral nerves (polyneuropathy).

“About 2.4% of the world population is affected by peripheral nerve disorders; the

prevalence increases to 8.0% in older populations. Diabetic neuropathy occurs in

approximately half of the individuals with chronic type 1 and type 2 diabetes. Globally,

leprosy remains a common cause of peripheral neuropathy, with the highest prevalence in

South East Asia.”(2)

The pathophysiology of neuropathy depends on the cause and may occur by three basic

mechanisms of Segmental demyelination, Wallerian degeneration, or axonal degeneration.

(2)

“Mononeuropathies are disease or trauma involving a single peripheral nerve in isolation, or

out of proportion to evidence of diffuse peripheral nerve dysfunction. Mononeuropathy

multiplex refers to a condition characterized by multiple isolated nerve injuries.”(3)

“Disease involving the common peroneal nerve or its branches, the deep and superficial

peroneal nerves are known as peroneal mononeuropathies. Lesions of the deep peroneal

nerve are associated with paralysis of dorsiflexion of the ankle and toes and loss of

sensation from the web space between the first and second toe. Lesions of the superficial

peroneal nerve result in weakness or paralysis of the peroneal muscles (which evert the

foot) and loss of sensation over the dorsal and lateral surface of the leg”.(4)

The characteristic signs seen in our patient include foot drop, steppage gait/ equine gait,

and loss of sensory function below the level of the ankle joint. The patient had an inability to

dorsiflex the ankle joint due to the weakness of the dorsiflexors of the foot, which are

supplied by the deep peroneal nerves.(5) Due to the foot drop the patient was unable to lift

the foot while walking, which resulted in a characteristic steppage gait or equine gait.

(6) The superficial peroneal nerves provide sensory innervations to the major part of the

dorsum of the foot, the deep peroneal nerves provide innervation to the first interdigital

cleft region, the sural nerve to the lateral margins of the dorsum, and the saphenous nerve

to the medial margins of the dorsum of the foot. A complete loss of all sensations (fine

touch, crude touch, pain, temperature, vibration, and proprioception senses) is seen below

the level of the ankle, suggesting the involvement of these nerves in the disease process.(7)

Foot drop may occur by compressive disorders, traumatic injuries, and neurologic

disorders.

Compressive disorders include prolonged bedridden status, tight casts, space-occupying

lesions, and bone metastasis involving the fibular head, etc. Traumatic injuries

include orthopedic injuries such as knee dislocations, fractures, blunt trauma, and

musculoskeletal injuries, surgeries. Neurologic disorders include ALS (Amyotrophic lateral

sclerosis), Cerebrovascular disease, AIDS, leprosy, hepatitis, granulomatosis with polyangiitis

(Wegener granulomatosis), and rheumatoid arthritis, Guillain-Barré syndrome,

Charcot–Marie Tooth syndrome .(5)

Learning Outcomes

Mononeuropathies present with varying symptoms depending on the nerves involved. In our patient, the peroneal nerves and the distal tibial nerves of the left foot were involved which lead to the subsequent symptoms of foot drop with equine gait and loss of sensation below the level of the ankle.

The patient had traveled from his home state to our hospital for a consultation. The patient's history was taken using a translator because of a language barrier. A thorough history and examination were done. A PaJR group was set up in which the case was discussed extensively with various doctors and medical students to understand the pathology in the patient and find out the etiology of his condition. The PaJR group enabled us to monitor the patient from time to time and record all new findings in chronological order. 

Various investigation modalities were included like MRI, High-resolution ultrasound,  and Nerve conduction studies to explore the possible etiologies in the case, all of which suggested pathology involving the peroneal nerves and the distal tibial nerves in the left foot.

A Slit Skin smear was conducted to rule out Hansen's disease .

Treatment given included Gabapentin tablets 100 mg, Multivitamin supplements and amitriptyline tablets 25mg. 

Due to financial constraints, the patient could not continue to stay at the hospital and had to return to his livelihood of farming. 

The SWOT analysis of the PaJR patient -

Strength -

The PaJR group enabled us to discuss the case extensively and monitor the patient .

The PaJR group proved to be a platform where various doctors were informed of any new

findings and condition of the patient and enabled them to give their inputs about the case.

Weakness-

Since the patient was not literate and could not afford a phone that was compatible with the

the platform on which the PaJR group was created, the patient was not able to update any

new findings or his health status in the group after his discharge.

Opportunities -

The PaJR group provided an opportunity for many medical students and doctors to get an

insight into the case and present their individual discussion about the case.

It also provided a platform where the patient's attender could update his condition.

The discussion in the PaJR group can be referenced for any case research in the future.

Threat -

Multiple inputs can cause confusion about the etiology and treatment of the disease.

TIMELINE