Sex: F
Vaccine: FLUX
Symptoms: Nerve conduction studies abnormal, Nerve conduction studies normal, Neurilemmoma benign, Neurological examination abnormal, Nuclear magnetic resonance imaging abnormal
Clinical narrative: This literature case, initially received on 03-Sep-2018 and concerns a 28-year-old, adult, female patient. The patient did not take any medications at the time of vaccination and had no family history of neuromuscular disorders. The patient had no exposure to cholesterol-lowering agents, including statins, herbal medication, or recreational drugs. On an unspecified date, the patient was administered with Influenza vaccine (dose, route of administration, anatomical location, batch number, expiry date, trade name, manufacturer: not reported). On an unspecified date, 2 weeks after receiving the annual influenza vaccination, the patient presented to hospital with profound muscle weakness. The patient denied any fever, chills, skin rashes, or other complications after the vaccination. The muscle weakness began in the calves and thighs and spread rostrally to her trunk and arms over the course of 3 weeks. At initial presentation, 5 weeks after vaccination, the patient could not lift her arms or legs and there was a mild muscle tenderness. The patient denied any visual disturbance, ptosis, dysarthria, dysphagia or cognitive impairment. Neurological examination showed marked proximal weakness in her upper and lower extremities: strength of 4/5 in the Medical Research Council (MRC) scale in neck flexion, mild bifacial weakness, 3/5 in proximal upper and lower extremities but 5/5 in hands and feet. Reflexes were absent in the upper extremities and 1+ in the lower extremities. Initial creatine phosphokinase (CK) was found to be 16,095 U/L, which remained elevated despite hydration, initiated for presumed rhabdomyolysis. The first muscle biopsy was reportedly inconclusive. The patient was briefly treated with 40-mg daily prednisone without response. The patient's condition continued to worsen and was presented 1 month later with a significant head drop, dyspnea, dysphagia, 20-pound weight loss, hypophonia, and fatigue. Motor exam this time showed (in MRC): deltoid 1/5, biceps 3/5, triceps 2/5, wrist flexion 42/5, wrist extension 4-5, abductor pollicis brevis 4/5, first dorsal interosseous 4/5, iliopsoas 1/5, quadriceps 3/5, hamstring 3/5, ankle dorsiflexion, and plantar flexion 4/5 bilaterally. Nerve conduction studies (NCSs) were abnormal, with decreased compound muscle action potential amplitudes, normal onset latencies, and normal conduction velocities in the left median and ulnar nerves. At the local hospital, the patient was diagnosed with acute motor axonal neuropathy (AMAN), a variant of Guillain-Barre syndrome (GBS). Subsequently, the patient was treated with a five-day course of IV immunoglobulin (IVIg) with minimal improvement. The patient was then discharged to a long-term rehabilitation facility and required feeding tube insertion. The condition of the patient continued to deteriorate and was admitted to hospital again due to the possibility of alternative disease beyond AMAN. Upon admission, the patient was afebrile but seemed chronically ill. A mild sinus tachycardia was noted on ECG and ophthalmic, cardiac, pulmonary and abdominal examinations were unremarkable. Neurological examination revealed continued muscle groups (proximal more than distal), diffuse muscle atrophy, severe facial and bulbar weakness and head drop. The sensation was intact, but the reflexes were globally absent. A second NCS showed moderately reduced compound muscle action potential with normal latencies and conduction velocities. Sensory NCS was completely normal. Electromyography revealed abundant fibrillation potentials and positive sharp waves in all tested muscles, and diffuse myopathic units. CK level remained elevated at 11,699 U/L and troponin T was elevated at 3.6 ng/ml. The Echocardiogram and cardiac MRI were unremarkable without signs of myocarditis or pericardial effusion. Thigh MRI showed diffuse edema on Short T1 Inversion Recovery and T2 sequences. Muscle biopsy from the left rectus femoris muscle showed discrete necrotic fibres with phagocytosis and concurrent regenerating fibres. Lymphocytic inflammatory cell infiltration was absent. There was no evidence of perifascicular atrophy or increased endomysial fibrosis. These pathological features were consistent with IMNM with minimal inflammation. Extensive rheumatologic workup showed normal complements 3, C4, and all but one of the myositis-specific antibodies (Jo-1, PL-7, PL-12, Mi-2, Ku, EJ, and OJ) returned negative, including S-A, SS-B, DNA, RNP, Smith, ANA, and anti-HMGCR. The anti-SRP antibody returned moderately positive. Chest and abdominal CT scans, performed to exclude malignancy, found a retroperitoneal mass which was diagnosed as benign schwannoma and was removed surgically. The patient was treated with IV SOLU-MEDROL 1 g daily for 5 days. Despite the treatment, the patient developed respiratory failure and required intubation. Eventually, IVIg (2g/kg for 5 days) started along with rituximab 375 mg/m2 which showed clinical improvement and down trended the serial CK values from 11,700 to 960 U/L after 5 weeks. The patient's strength lagged in improvement compared with her laboratory studies and eventually required tracheotomy. The monthly IVIg was continued for 6 months and was tapered off while in rehabilitation facility. At her outpatient visit, 15 months after initial presentation, both the feeding tube and tracheotomy were removed. The patient could ambulate without assistance but still had difficulty to climb stairs and past CK was found to be 289 U/L. Motor examination showed significant improvement with mild proximal weakness 4-4+/5 in MRC score in the deltoid, biceps, iliopsoas, and hamstring muscles. At the time of this report, the outcome of the events was recovering. The onset of the events within 2 weeks after receiving influenza vaccination suggested the possible association (related) to the vaccination. Vaccines could stimulate autoantibody production through molecular mimicry to the virus or bacteria itself in the vaccination, alive or not. It has been demonstrated that the vaccinations could also trigger inflammatory responses known as autoimmune/inflammatory syndrome induced by adjuvants (ASIA). The reporter assessed the events as serious due to hospitalization.