CEREBRAL INTRACRANIAL HYPERTENSION WITH FREE FLUID IN  BRAIN BEHIND  EYE; FLARED UP ARTHIRITIS; This spontaneous report received from a patient and concerned a 52 year old, White, not Hispanic or Latino, female. Initial information was received on 16-APR-2021 from the patient, with additional information received on 20-APR-2021 from the patient.  The patient's weight was 170 pounds, and height was 65.5 inches. The most recent body mass index was 27.9. The patient's family history included rheumatoid arthritis in father, and concurrent conditions included arthritis (possibly rheumatoid arthritis), chronic back pain, and hip pain. The patient was due for a surgery, but it was cancelled due to pandemic. She had no history of headaches or migraines. Patient received several unspecified vaccines (had several vaccines 3 years ago before trip ) with no problems. The patient received covid-19 vaccine ad26.cov2.s (suspension for injection, route of admin not reported, batch number: 1805020 expiry: UNKNOWN) dose was not reported, administered on 15-MAR-2021 on right arm for prophylactic vaccination. Concomitant medications included acetylsalicylic acid 81 mg, daily, ascorbic acid, ergocalciferol, metaxalone, oxycodone, and zinc. The patient concurrently receives spinal/epidural pain injections every two to three months.  Approximately 16-30 hours after the vaccination, she had a flare up of her arthritis (left hip, L3, L4, L5, sciatic pain on the left side going all the way down to her knee, ankle, and foot, where her normal arthritis hurts daily). Pain medication did not help. She also developed migraines which caused pain behind the left eye similar to severe sinus infection, light sensitivity, her face felt tingly and numb in her temples and cheeks (left side). She was concerned about a stroke, but did not have droopiness and could smile on both sides. On 29-MAR-2021 (day 14 post vaccination), the patient went to her pain specialist to receive her spinal/epidural pain injection because she was in a lot of pain and she was "overdue". In retrospect, the patient wondered if she should have waited longer after having received the vaccine before doing so. On 30-MAR-2021 (day 15 post vaccination), she awoke and was blind for several (12 - 14) hours. She thought she had a stroke and took 4 baby aspirins. She was rushed to the hospital and was hospitalized on 30-MAR-2021. After the initial 2-3 hours that she was completely blind, it would come back within minutes. The vision came back in halos. It was blurry but if she moved or bent down, it would go again and then it would come back very quickly. Several tests were performed. The MRI (Magnetic resonance imaging) did not show clots, stroke, or tumors, but showed intracranial hypertension. After the CT and MRI, a lumbar puncture was performed (results not provided). The patient said that the hospital noted cerebral intracranial hypertension with free fluid in her brain behind her eye. In the hospital, bloodwork was normal except for her triglycerides which were high. Patient reported that her platelet levels which were "perfect" and provided "318" as a specific example. She was discharged on 01-APR-2021.  Corrective treatments included: steroids in the hospital for the intracranial hypertension and prescription strength aspirin 325 mg. The patient was not certain if injectable blood thinners were given to her in the hospital. She was discharged with methylprednisolone, alprazolam, twice a day prn to treat her headaches, aspirin 325 mg daily, and rosuvastatin 5 mg, daily, for high triglycerides. After patient was discharged, she had 2 episodes of lightheadedness with the blindness. The first one lasted about 5 minutes maximum and the second one on 12-APR-2021 lasted approximately  30-40 minutes. She had to be sitting down and her vision returned in halos with a lot of fireworks like bright stars. The patient had ringing in the ears, especially the left ear and when she had these episodes. On 14-APR-2021, the patient patient went to PCP (primary care provider). She stated that alprazolam helps her headaches. On 20-APR-2021, she had a "good day", did not experience headaches, and did not take alprazolam. She will follow up with a neurologist and an ophthalmologist. The action taken with covid-19 vaccine ad26.cov2.s was not applicable. The outcome of the cerebral intracranial hypertension with free fluid in brain behind eye and flared up arthritis were not reported. This report was serious (Hospitalization Caused / Prolonged, and Other Medically Important Condition).; Sender's Comments: V0: This 52 year-old White female was hospitalized for intracranial hypertension 15 days after receiving the Janssen Covid-19 vaccine.  Medical history includes an unspecified arthritis with chronic left hip and back pain for which she receives epidural injections every 2-3 months, and a body mass index of 27.9. She has no history of migraines or other headaches and has tolerated multiple vaccinations previously. Concomitant medications include acetylsalicylic acid 81 mg daily, metaxalone, and oxycodone. Approximately 16 hours after vaccination, she experienced a flare of her arthritis which her pain medications did not relieve. The next day, she began to experience migraine headaches which were associated with pain behind her left eye and sinuses, left-sided facial tingling and numbness without weakness, and light sensitivity.  Fourteen days post-vaccination, she received an epidural injection because she was in a lot of pain. The following morning, she awoke and experienced visual disturbance, described as "complete" blindness. then return of vision with halos and blurriness, and intermittent loss and return of vision depending on her body position. She took 4 baby aspirins, went to the hospital, and was admitted. MRI showed intracranial hypertension but no clots, stroke, or tumors. A lumbar puncture and CT scan were also performed. Blood tests, including platelet counts (e.g. 318), were normal except for high triglycerides. She was treated with steroids and aspirin 325 mg and was discharged 2 days later. She was given methylprednisolone, oxycodone-acetaminophen and alprazolam prn for headaches, aspirin 325 mg, and rosuvatstatin for high triglycerides to continue at home and will follow up with a neurologist, ophthalmologist and her primary physician. Based on the available information, the relationship of intracranial hypertension with Janssen Covid-19 vaccine is considered inconsistent.