ACUTE MOTOR-SENSORY AXONAL NEUROPATHY; CERVICAL STENOSIS; HYPOXIA; SYMPTOMATIC BRADYCARDIA; HOARSENESS; LIGHTHEADEDNESS; This spontaneous report was received from literature. This report concerned a 49 year old female of unspecified ethnicity.  The objective of this study is to describe a rare variant of GBS with a temporal relation to the Ad26.COV2.S. The patient's height, and weight were not reported. The patient's concurrent conditions included: neurofibromatosis type 1, hypothyroidism, and multiple vitamin deficiencies and the patient was healthy. The patient's history was negative for any recent illnesses, changes to medications or lifestyle, domestic or international travel or exposure to any known sick contacts. The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin not reported, batch number: Unknown and expiry: UNKNOWN) dose, start therapy date were not reported,1 total administered for prophylactic vaccination. The batch number was not reported and has been requested. No concomitant medications were reported. It was reported that on an unspecified date the patient was presented to her primary care physician with new-onset numbness in her extremities for a duration of one day. She experienced reduced tactile sensation and numbness in her right upper extremity, extending from the elbow into her hand and bilateral lower extremities from her knees through her feet. She had associated headache with pain to palpation across her forehead, lightheadedness, and aching lumbar pain of four days duration. The patient received the vaccine five days prior to the onset of her symptoms. Later due to acute neurological involvement of her multiple extremities with reduced tactile sensation, the patient was directed immediately to the emergency department for further evaluation. During the initial emergency department evaluation, the patient endorsed difficulty walking and holding objects in addition to the previously reported symptoms. These difficulties were thought to be secondary to altered sensation rather than resulting from musculoskeletal weakness. Physical exam revealed orbital, jaw, and neck pain to palpation. The patient was afebrile, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) negative, and showed no signs of infection or electrolyte abnormality on initial complete blood count (CBC), comprehensive metabolic panel (CMP), and urinalysis (UA). Thyroid-stimulating hormone, free thyroxine, and muscle-specific kinase antibodies were within normal limits. The only abnormal blood work seen was an equivocal B12 level of 187 ng/L (normal 180-914 ng/L). She also underwent an MRI of her brain and cervical spine for concerns of multiple sclerosis given her multiple neurologic symptoms. Brain MRI revealed small punctate foci inconsistent with multiple sclerosis or acute neurologic findings. Due to equivocal B12 levels and non-specific MRI findings, the patient was given a B12 injection and discharged to her home with instructions for outpatient follow-up with neurology. It was also reported that the patient returned to the emergency department next day with worsening generalized weakness and paresthesia. The patient also noted new hoarseness and dysphagia, thoracic back pain, and urinary incontinence that had all developed within the 16 hours since her emergency department (ED) discharge. In ED (emergency department) triage, the patient collapsed to the floor without loss of consciousness or seizure activities. She was afebrile, hypertensive to 171/98, and hypoxic with oxygen saturation in the mid-80s.Her physical exam was positive for symmetric weakness in bilateral lower extremities. A CT (Computed Tomography) angiogram of the chest was ordered for concerns of a developing aortic dissection, which was unremarkable. Additional imaging was then ordered, with an MRI of the brain, which showed moderate cervical stenosis. MRI of the thoracic and lumbar spine was also conducted but was otherwise unremarkable. Her lumbar puncture revealed elevated albumin (normal less than 27.0 mg/dL) and IgG (normal less than 8.1 mg/dL) without signs of meningitis or multiple sclerosis and the patient was admitted to the medical intensive care unit (MICU) due to her rapidly progressing neurological symptoms. The patient's physical examination was notable for bilateral extraocular muscles weakness, decreased pinprick sensation in all four extremities, with preserved temperature and vibratory sensation, 4 out of 5 strengths in the right upper extremity, bilateral proximal lower extremities, and bilateral finger flexion, with preserved 5 out of 5 strengths in the left upper extremity. Additionally, reflexes were tested and showed 1plus in bilateral biceps and brachioradialis and absent at the bilateral patella and achilles. By hospital day 4, the patient became almost quadriplegic, along with bilateral facial nerve paralysis and a weak gag reflex. She required bilevel positive airway pressure (BiPAP) initially and eventually intubation. Given her rapid neurological decompensation, with sensory symptoms with negative workup and recent history of vaccination, clinically, neurology suspected this was a rare variant of GBS called acute motor and sensory axonal neuropathy (AMSAN). She was started on intravenous immunoglobulin (IVIG). On hospital day 13, she remained intubated without significant improvement despite four days of IVIG. She developed symptomatic bradycardia that required pacemaker placement. On hospital days 23-32, the patient received a course of plasmapheresis, due to lack of clinical improvement, and a tracheostomy. On hospital days 33-54, the patient underwent physical rehab and ventilatory weaning at Select Hospital. On hospital days 54-63, the patient was readmitted by neurology for a second round of plasmapheresis and an additional dose of IVIG. Following these treatments, she had gradual improvement in her weakness. On hospital day 64, the patient was transferred back to hospital. Laboratory data (dates unspecified) included: Albumin (NR: 0.0 - 27.0) 46 mg/dL, Anti-muscle specific kinase antibody (NR: not provided) within normal limits, Blood pressure (NR: not provided) 171/98 mmHg, Body temperature (NR: not provided) afebrile, preserved, CSF oligoclonal band (NR: not provided) Negative(reference-negative), CT pulmonary angiogram of the chest was ordered for concerns of a developing aortic dissection, which was unremarkable, Complete blood count (NR: not provided) no abnormality, Comprehensive metabolic panel (NR: not provided) no abnormality, Glucose (NR: 40 - 80) 77 mg/dL(reference-40-80 mg/dL)(CSF Values ), IgG (NR: 0.0 - 8.1) 8.8 mg/dL(reference-0.0-8.1 mg/dL) (CSF Values ), IgG (NR: not provided) elevated, Lumbar puncture (NR: not provided) abnormal, MRI (NR: not provided) unremarkable, Oxygen saturation (NR: not provided) mid-80s, Physical examination (NR: not provided) orbital, jaw, neck pain, abnormal, positive, Protein (NR: 15 - 60) 58 mg/dL(reference-15-60 mg/dL)(CSF Values ), Red blood cell count (NR: 0 - 10) 368(reference-0-10 RBC/mcL) )(CSF Values ), SARS-CoV-2 test (NR: not provided) Negative, Sensory level (NR: not provided) negative workup, Thyroid stimulating hormone (NR: not provided) within normal limits, Thyroxine (NR: not provided) within normal limits, Urinalysis (NR: not provided) no abnormality, Vitamin B12 (NR: 180 - 914) 187 ng/L, and WBC (NR: not provided) 0(reference- less than 5 lymphocytes/mcL)(CSF Values ).  The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The outcome of the lightheadedness, hoarseness, hypoxia, symptomatic bradycardia, cervical stenosis and acute motor-sensory axonal neuropathy was not reported. The Author concluded that the unique presentation of the rare variant of GBS, AMSAN, can make a prompt diagnosis challenging and difficult. When evaluating patients with progressive paralysis with and without neuropathy, GBS should remain in the differential, even if patients do not follow exactly the characteristic stocking and glove pattern. Early involvement of the neurology team in suspected cases may help diagnose patients presenting with some of the unique neurological features, ultimately allowing for quicker intervention. This report was serious (Hospitalization Caused / Prolonged, and Life Threatening).; Sender's Comments: V0: 20211061265-covid-19 vaccine ad26.cov2.s- cervical stenosis, hypoxia, symptomatic bradycardia, lightheadedness, hoarseness. This event(s) is considered unassessable. The event(s) has a compatible/suggestive temporal relationship, is unlabeled, and has unknown scientific plausibility. There is no information on any other factors potentially associated with the event(s). 20211061265-covid-19 vaccine ad26.cov2.s-Acute motor-sensory axonal neuropathy . This event(s) is considered related. The event(s) has a compatible/suggestive temporal relationship, is unlabeled, and is scientifically plausible. There is no information on any other factors potentially associated with the event(s).