A 37-years-old female patient presented with complaints of pain in the left arm since three months followed by weakness a month later. The patient had dull boring pain around the left shoulder which radiated on lateral aspect of left arm. The pain progressed over 15 days to involve lateral forearm as well as the thumb and the index finger. This pain did not interfere in her daily activities and would respond partly to analgesics. After about a month, she noticed acute onset weakness in raising her left arm above the shoulder. The weakness progressed over a day to involve the entire left limb and she was unable to flex her elbow or grip objects. The patient also had decreased perception of hot and cold as well as texture of clothes. The patient had noticed that her left shoulder appeared thinner than the right and had history of occasional fasciculations in that region. There was no history of weakness or sensory loss in lower limbs or bladder bowel complaints. The patient had no history of fever, cough with expectoration or hemoptysis, trauma, weight loss, diabetes mellitus or hypertension. The patient did not complain of arthralgia, arthritis, rash or oral ulcers. She denied recent vaccination or unsafe sexual practices. With these above complaints, she consulted neurologist and was subjected to nerve conduction studies and electromyography and was diagnosed to have idiopathic left upper trunk brachial plexopathy. The patient was started on oral steroids, pain subsided transiently and the weakness did not respond to treatment. After about a month's therapy, she started noticing similar complaints in the right arm and at that time she was referred to our center for further evaluation and management. When the patient was presented in our outpatient department, she had developed painful weakness in both upper limbs (left > right) along with paraesthesia in both arms.
On examination, she was conscious, oriented and had normal higher mental functions. Cranial nerve examination was normal. Wasting was noted around the left shoulder girdle and left arm. The patient had hypotonia in both upper limbs. The power was grade 2 at shoulder joint, grade 3 at elbow joint, grade 4 at wrist extension and grade 5 at wrist flexion in the right upper limb as per Medical Research Council (MRC) grade. On the left side, power was MRC grade 2/5 at shoulder joint, 2/5 at elbow joint, 3/5 at wrist extension, 4/5 at wrist flexion and hand grip weakness was noted. The patient had normal power in both lower limbs. Deep tendon jerks in bilateral biceps, triceps, supinator were absent, ankle and knee jerk were normally elicitable. Bilateral plantar reflexes were flexor and abdominal reflex were present in all 4 quadrants. Sensory examination revealed about 30% loss in pin prick sensation in left arm in C5-C7 dermatome. Joint position and vibration sensation were impaired in the upper as well as lower limbs. The patient had positive Romberg's sign. There were no cerebellar signs, thickened nerves, stigma of tuberculosis or syphilis. No lymphadenopathy or spine abnormality was noted.
Complete hemogram, fasting blood sugar, renal and liver function tests were within normal range. Erythrocyte sedimentation rate was 24 mm at the end of one hour by Westergren method. C-reactive protein and anti- nuclear antibodies were negative. Anti-neutrophilic antibody (cANCA and pANCA), extractable nuclear antigens (ENA), serum were negative and cerebrospinal fluid (CSF) angiotensin converting enzyme (ACE) level was within normal limits. Microscopy of CSF revealed 10 cells, all of which were lymphocytes. CSF biochemistry showed protein 48 mg/dl and CSF sugar 67 mg/dl (corresponding blood sugar: 98 mg/dl). CSF for oligoclonal bands was positive. The CSF virology assessment for HSV PCR and IgM antibodies against herpes simplex, cytomegalovirus, Japanese encephalitis, varicella zoster virus, dengue and Epstein Barr virus was negative. Enzyme linked immunoassay (ELISA) for human immunodeficiency virus I and II was negative. Hepatitis B surface antigen (HBsAg) and anti- HCV antibody were also negative. Polymerase chain reaction for M. tuberculosis was negative. Cancer antigen 125 (CA-125) level was 45.39 U/ml (normal value below 35 U/ml). Onconeural antibodies could not be performed. The repeat nerve conduction studies revealed left sided pan-plexopathy and right upper trunk plexopathy. Electromyography was suggestive of denervation and showed fibrillation, fasciculations and large amplitude motor unit action potentials.
Magnetic resonance imaging (MRI) of cervical spine showed mild swelling of the cord along with hyperintense signals within the spinal cord on T2 weighted images. In addition, hyperintensities of multiple radicles were noted bilaterally on T2 fat suppression images [Figure 1]. Incidentally, MRI revealed an ill defined, heterogeneously enhancing lesion (4 x 3 x 3 cm3) in the left upper lung [Figure 1]. Computed tomography (CT) thorax showed well defined heterogeneously enhancing soft tissue attenuation lesion with speculated margin in apico posterior segment of left upper lobe [Figure 2]. Rest of the lung parenchyma was normal and no significant mediastinal lymphadenopathy was noted. CT guided fine needle aspiration cytology revealed malignant epithelial cells lying in clusters in a hemorrhagic background [Figure 3].
The patient received intravenous methylprednisolone 1 gm/day for 5 days followed by oral prednisolone 1 mg/kg/day for one month. After the confirmation of the lung malignancy on follow up imaging, she was referred to oncology and was advised chemotherapy followed by radiotherapy.
MRI cervical spine [Figure 2] done after one month of steroid therapy showed disappearance of the cord hyperintensity but the mass lesion had increased significantly in the size (6 x 4 x 6 cm3). The arm pain had responded but weakness persisted. The patient is currently receiving chemotherapy and radiotherapy.
(d) STIR coronal view shows resolution of signal changes in the nerve roots. Figures e and f shows contrast enhancing rounded opacity in the apex of left lung on computed tomography of chest.