Page 100 - TD-3-1

Tumor Discovery

CASE REPORT
Compressive neuropathy of the branch of the

posterior interosseous nerve with isolated
paralysis of the extensor digitorum longus

muscle: A case report

Balaji Zacharia *, Puneeth K. Pai , and Vishnu Unnikrishnan 2
2
1
1 Department of Orthopedics, Government Medical College, Kannur, Pariyaram, Kerala, India
2 Department of Orthopedics, Government Medical College, Kozhikode, Kerala, India

Abstract

Compressive neuropathies occur when a nerve is compressed in a closed osteofibrous
tunnel. Here, we report a case of isolated paralysis of the extensor digitorum longus
muscle due to compression of a branch of the posterior interosseous nerve (PIN) in
the proximal forearm in a 56-year-old man presented with progressive weakness
of the left hand over 18 months. During the first time of clinical consultation, we
found a swelling in the extensor aspect of the left proximal forearm, and a firm, non-
tender, mobile swelling located deep in the extensor muscles, without other muscle
involvement. The sensation was intact. An ultrasound scan and magnetic resonance
imaging scan confirmed the diagnosis of an intramuscular lipoma, which was further
confirmed with histopathologic examination. The patient was treated with an
*Corresponding author: excision of the lipoma and decompression of the nerve. Post-operatively, the patient
Balaji Zacharia was given regular physiotherapy, through which he achieved improvement in his
(balaji.zacharia@gmail.com) finger extension within a year. This is an extremely rare case of isolated paralysis of
Citation: Zacharia B, Pai PK, the extensor digitorum longus due to compression of the branch of the PIN by an
Unnikrishnan V. Compressive intermuscular lipoma in the forearms.
neuropathy of the branch of the
posterior interosseous nerve
with isolated paralysis of the
extensor digitorum longus muscle: Keywords: Posterior interosseous nerve palsy; Finger drop; Extensor digitorum longus
A case report. Tumor Discov. paralysis; Intramuscular lipoma
2023;3(1):1585.
https://doi.org/10.36922/td.1585
Received: August 11, 2023
Accepted: November 15, 2023 1. Background
Published Online: December 1, 2023
Compressive neuropathies are caused by increased pressure in the nerves as the nerve
Copyright: © 2023 Author(s).
This is an Open-Access article pass through a closed osteofibrous tunnel, whose capacity is not commensurate with the
distributed under the terms of the content. In most cases, compressive neuropathies are idiopathic. The peripheral nerve
Creative Commons Attribution
License, permitting distribution, is usually resistant to acute microvascular compressive changes due to low pressure.
and reproduction in any medium, Prolonged compression of the nerve can cause increased intracellular permeability,
provided the original work is
properly cited. leading to interfascicular edema and a delay in nerve conduction. Large-diameter nerve
fibers are more susceptible to compression. Friction and traction can also cause nerve
Publisher’s Note: AccScience [1]
Publishing remains neutral with ischemia. Compressive neuropathies rarely occur in radial nerve .
regard to jurisdictional claims in
published maps and institutional Compressive neuropathies may occur as a result of neural sheath tumors and non-
affiliations. neural sheath tumors. Ganglioma, lymphangioma, hemangioma, myeloblastoma,

Volume 3 Issue 1 (2024) 1 https://doi.org/10.36922/td.1585