SYNDROME OF INAPPROPRIATE ANTIDIURETIC HORMONE; PSEUDOHYPONATREMIA; URINE TOXICOLOGY/ URINE DRUG SCREEN TEST POSITIVE FOR TETRAHYDROCANNABINOL; ATYPICAL GUILLAIN-BARRE SYNDROME; This spontaneous report was received from literature: Guillain-Barre Syndrome Presenting as Facial Diplegia after COVID-19 Vaccination: A Case Report. The Journal of Emergency Medicine. 2021 Aug 07;1-5. This report concerned a 38-year-old male of unspecified race and ethnic origin. The objective of this report was to describe a case of an atypical presentation of GBS (Guillain-Barre Syndrome) presenting with extremity paresthesias, dysarthria, and bilateral facial weakness in the absence of classic ascending limb weakness, and discuss differential diagnosis, triage, and management. The patient's height, and weight were not reported. The patient's concurrent conditions included: Anxiety, depression, alcohol user (average of 6 to 8 beers per day), and marijuana user (daily). The patient had been in a state of good health upon receipt of the vaccine 32 days prior. The patient received covid-19 vaccine adv26.cov2.s (suspension for injection, route of admin not reported, batch number: unknown, 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. Concomitant medications included bupropion for anxiety and depression. On an unspecified date, approximately 2 weeks after vaccination, the patient experienced subacute, rapidly progressive, numbness and tingling in the tongue, lips, bilateral hands and feet/ paresthesias. Two days prior to presentation the patient began to develop difficulty moving his mouth, forming words/ dysarthria/slurred speech, bilateral facial weakness/ facial diplegia/bilateral facial nerve palsy in a lower-motor-neuron pattern with acral paresthesias variant and an absence of classic ascending limb weakness, as well as difficulty drinking from a straw and controlling the lips, cheeks and tongue while eating. The review of systems was notable for headaches, mild gait unsteadiness, generalized fatigue and dyspnea on exertion. The patient denied diplopia, dysphagia, or dysphonia, chest pain or palpitations, lightheadedness, fevers or chills, nausea, vomiting or diarrhea, urinary or bowel incontinence and falls or other trauma. The patient visited the emergency department in a clinically good condition, not in acute distress and was ambulating independently. Initial vital signs were as follows, blood pressure 218/80 mmHg, heart rate 85 beats/min, respiratory rate 16 breaths/min and oxygen saturation of 100%. The patient exhibited weak eye closure bilaterally and inability to smile or puff cheeks against resistance. The extraocular movements were intact and tongue was midline without fasciculations. Strength in the upper and lower extremities were intact (5/5) as sensation to light touch throughout. There was no dysmetria or gait ataxia. Deep tendon reflexes were reduced 1 plus in the lower extremities and only faintly present in the bilateral upper extremities. Laboratory data were notable for a white blood cell count of 12.25 x 10E3/mL with a normal differential, hemoglobin of 16.7 gram per deciliter, and a hematocrit of 49.5 L/L. The serum chemistries including liver function test, thyroid-stimulating hormone, folate, and B12 (Cobalamin), were all within normal limits. Urine toxicology/ Urine drug screen test was positive for tetrahydrocannabinol and covid-19 polymerase chain reaction was negative. A neurology consultation was obtained. The brain magnetic resonance imaging (MRI) with and without contrast and constructive interference in steady state (CISS) sequencing revealed focal enhancement of the bilateral internal auditory canal fundi which carried the CN-VII (cranial nerve) and CN-VIII and the bilateral cisternal segments of the trigeminal nerves. Cerebrospinal fluid (CSF) analysis revealed glucose of 73 mg/dL, an elevated protein to 181 mg/dL, and 7 nucleated cells/high-power field (HPF; corrected for 2987 red blood cells/HPF), constituting albuminocytological dissociation suggestive of atypical Guillain-Barre syndrome. The electrodiagnostic evaluation was not performed as the CSF profile and clinical presentations were definitive of GBS. The patient was hospitalized and received intravenous immunoglobulin (IVIG) over 2 days to a total dose of 2 grams per kilo gram body weight, which showed a mild improvement in his symptoms. Measurements of negative inspiratory force was performed daily, and the patient had not developed any signs or symptoms of respiratory compromise. On hospital day 1, the patient developed new hyponatremia, which had reached a value of 124 mEq/L (milliequivalents per litre) during admission which was concluded to be multifactorial, attributed to pseudohyponatremia in the setting of IVIG as well as syndrome of inappropriate antidiuretic hormone in the setting of GBS. The patient was treated with fluid restriction and salt tabs with improvement in sodium to 134 mEq/L on discharge. The patient's symptoms showed no further progression and was discharged home on hospital day 4. The duration of hospitalization were 4 days. The discharge examination was notable for stable to improvement in bilateral facial weakness and dysarthria with generalized areflexia. The author concludes that the patient received the Johnson and Johnson vaccine against the COVID-19 virus 32 days prior to presentation. In the Johnson and Johnson COVID19 vaccine trial, one case of GBS in the post-vaccination arm was reported, however, there was also a case of GBS in the placebo arm. This did not imply a causal association between the Johnson and Johnson COVID-19 vaccine and GBS. Author cannot say definitively whether the patient's prior vaccination contributed to his development of GBS or was incidental to it. The risk of developing vaccine-associated GBS remains very low when viewed across the general population, and cases of GBS with a temporal association to vaccination are not necessarily caused by a vaccine-mediated immune response. Overall, the benefits of vaccination to prevent COVID-19 infection likely outweigh the risks of any potential adverse effects, including GBS, as stated in recent guidelines from the centers for disease control and world health organization. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The patient was recovering from syndrome of inappropriate antidiuretic hormone, pseudohyponatremia, and atypical Guillain-Barre syndrome, and the outcome of urine toxicology/ urine drug screen test positive for tetrahydrocannabinol was not reported. This report was serious (Hospitalization Caused / Prolonged).; Sender's Comments: V0: 20210941304-covid-19 vaccine ad26.cov2.s- pseudohyponatremia, syndrome of inappropriate antidiuretic hormone, Urine toxicology/ Urine drug screen test positive for tetrahydrocannabinol. 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). 20210941304-covid-19 vaccine ad26.cov2.s-atypical Guillain-Barre syndrome. This event(s) is labeled per RA and is therefore considered potentially related.