Age: 66.0
Sex: M
Vaccine: FLUX, FLUX
Symptoms: Aldolase normal, Antibody test negative, Areflexia, Blood creatine phosphokinase normal, Blood immunoglobulin G normal
Clinical narrative: Multifocal Motor Neuropathy; Sensation of blurred vision in the left eye with some drooping; Sensation of blurred vision in the left eye with some drooping; This literature case was retrieved on 04-May-2022 from Vaccine Adverse Event Reporting System (VAERS) (reference number: 2245507-1) with additional document received on the same day (being processed together), reported by other healthcare professional and concerned a 66-year-old, male patient.   The patient's past medical history included tobacco use. The patient's concomitant medications were not reported.   On an unspecified date, the patient was vaccinated with influenza vaccine (brand not specified; route of administration, anatomical location, dose and indication: not reported). The batch number was not reported.  On an unspecified date, about ten days after receiving influenza vaccine, the patient presented with right greater than left upper extremity paresthesia as well as bilateral lower extremity weakness (right greater than left), numbness, and tingling in his fingertips. The patient also reported a sensation of blurred vision in the left eye towards the evening with some drooping. He denied any urinary symptoms, dysphagia, shortness of breath, fever, chills, chest pain, or facial droop. Initial vitals recorded on presentation were stable.  On an unspecified date, the patient was admitted to hospital. Physical exam was remarkable for decreased overall muscle bulk. Motor exam showed intact strength, 5/5, for bilateral upper and lower extremities. For upper extremity reflex testing, including biceps, triceps, and brachioradialis, the results were 1/4 bilaterally. Patellar and Achilles' tendon reflexes were absent bilaterally with fasciculations noted more prominent over the right lower extremity. Sensory exam was remarkable for diminished vibration sense over toes bilaterally and was intact at the knees and fingertips bilaterally. Light touch was preserved throughout the lower extremities. Lab workup including complete blood count (CBC), comprehensive metabolic panel (CMP), Lyme titers, creatine kinase (CK), aldolase, vitamin D, and B12 levels were within normal range. Myasthenia gravis antibody panel was negative. Magnetic resonance imaging (MRI) of head without contrast showed no acute intracranial abnormality. As the patient was afebrile and CBC was normal and no evidence of mental status changes cerebrospinal fluid (CSF) analysis was not done. He was further evaluated with an electromyography (EMG) with motor and sensory nerve studies. The EMG was interpreted as abnormal due to prolonged latency of right median compound muscle action potential (CMAP), and right peroneal CMAP, low conduction velocity (C.V.) of right ulnar CMAP, and low C.V. of right peroneal CMAP. The latency for right median nerve of elbow was 8.2 ms (reference range: 2.3-7.2 ms). The latency for right peroneal nerve at head of fibula was 11 ms, and at popliteal fossa 13.7 ms (reference range: 2.3-7.2 ms). The conduction velocity of right ulnar nerve at elbow was 48.5 m/s (reference range: 50-70 m/s) and for right peroneal nerve at popliteal fossa was 37.5 m/s (reference range: 40-70 m/s). Sensory nerve action potential (SNAP) was largely normal. The patient was also tested for the anti-GM1 antibody and his anti-GM1 IgM was positive with over 100% (reference range reported as 0- 30) and negative for the anti-GM1 IgG antibody. It was concluded that there was electrophysiologic evidence of a demyelinating motor neuropathy with evidence of conduction block, raising the possibility of atypical Guillain-Barre syndrome (GBS) or other acute inflammatory demyelinating polyneuropathy (AIDP) without evidence of sensory involvement. However, due to his motor involvement as evidenced by EMG studies that were more prominent in the upper than lower extremities, there was also a concern for multifocal motor neuropathy (MMN).  On an unspecified date, the patient was diagnosed with multifocal motor neuropathy and was treated with intravenous immune globulin (IVIG) at a dose of 0.4 g/kg daily for five days. The patient completed the course of IVIG with marked improvement of symptoms.   On an unspecified date, the patient was discharged to acute inpatient rehabilitation with Physical Therapy (PT) and Occupational Therapy (OT) and was also recommended to follow up as an outpatient. The patient was scheduled to receive 0.5 g/kg IVIG every 28 days following discharge.  On an unspecified date, about a month later, prior to the patient's scheduled IVIG infusion, the patient's clinical condition deteriorated at acute inpatient rehabilitation, necessitating him to be readmitted to the hospital. During the hospitalization, the patient was treated with plasmapheresis (five rounds of 3000 ml exchanges with 5% albumin).  On an unspecified date, the patient was discharged to acute inpatient rehabilitation. It was noted then that he was unable to ambulate independently following the second hospitalization. However, he was continued on monthly plasmapheresis (one round of 3000 mL exchanges with 5% albumin every 28 days) and participated in aggressive acute inpatient physical and occupational therapy rehabilitation.   Two months later, he was able to ambulate without assisted devices. Three months later, he was able to ambulate normally with only sensations of pins and needles in his hands, but with a normal neurologic examination.   At the time of initial report, the patient was recovering from the 'vision blurred', 'eyelid ptosis' and multifocal motor neuropathy, as it was reported that the patient continued with monthly plasmapheresis treatment and his disease had remained clinically quiescent for over a year, from the time of initial presentation.  This case was rare as the patient developed MMN with high anti-GM1 IgM antibody levels a few days after influenza vaccination. Patient also had motor impairment as evidenced by EMG studies. He was treated with IVIG with an improvement of his symptoms initially; however, later deteriorated and required plasmapheresis which was continued for maintenance therapy. Post-influenza vaccination MMN is a rare entity, which should be a differential in patients presenting with rapidly progressive neurological symptoms and features of GBS as rapid diagnosis and appropriate treatment can have better clinical outcomes. A thorough neurological examination and testing with EMG could aid in prompt diagnosis and management with anti-GM1 antibodies where appropriate. Although the literature review showed IVIG as a mainstay of treatment for MMN, the patient in this case report seemed to have a positive response while on plasmapheresis, after failing IVIG and has put his disease currently into remission.  The reporter did not provide a causality assessment.  The events of 'vision blurred', 'eyelid ptosis' and multifocal motor neuropathy were considered serious due to hospitalization. In addition the event of multifocal motor neuropathy was considered to be medically significant by a Physician within Seqirus' Pharmacovigilance and Risk Management Department.   Company comment: A 66-year-old patient experienced right greater than left upper extremity paresthesia as well as bilateral lower extremity weakness (right greater than left), numbness, and tingling in his fingertips, and blurred vision in the left eye with some drooping reportedly about ten days after receiving the suspect product influenza virus vaccine polyvalent. Thereafter, the EMG was interpreted as abnormal due to prolonged latency of right median compound muscle action potential (CMAP), and right peroneal CMAP, low conduction velocity (C.V.) of right ulnar CMAP, and low C.V. of right peroneal CMAP. The patient was also tested for the anti-GM1 antibody and his anti-GM1 IgM was positive with over 100% (reference range reported as 0- 30) and negative for the anti-GM1 IgG antibody. Based on the given results, the patient was diagnosed with multifocal motor neuropathy (MMN). Due to diagnostic findings and plausible temporal relationship, causality for the reported event is assessed as possibly related. Based on currently available information, causality for blurred vision and eyelid ptosis is unassessable.; Sender's Comments: A 66-year-old patient experienced right greater than left upper extremity paresthesia as well as bilateral lower extremity weakness (right greater than left), numbness, and tingling in his fingertips, and blurred vision in the left eye with some drooping reportedly about ten days after receiving the suspect product influenza virus vaccine polyvalent. Thereafter, the EMG was interpreted as abnormal due to prolonged latency of right median compound muscle action potential (CMAP), and right peroneal CMAP, low conduction velocity (C.V.) of right ulnar CMAP, and low C.V. of right peroneal CMAP. The patient was also tested for the anti-GM1 antibody and his anti-GM1 IgM was positive with over 100% (reference range reported as 0- 30) and negative for the anti-GM1 IgG antibody. Based on the given results, the patient was diagnosed with multifocal motor neuropathy (MMN). Due to diagnostic findings and plausible temporal relationship, causality for the reported event is assessed as possibly related. Based on currently available information, causality for blurred vision and eyelid ptosis is unassessable.