Small amount of bilateral subarachnoid hemorrhage; confusion; More tired; speech was a little bit thick/ speech is a little bit slurred; Tongue has been thick; Gait was slow with a shuffling gait; This spontaneous case was reported by a physician assistant and describes the occurrence of SUBARACHNOID HAEMORRHAGE (Small amount of bilateral subarachnoid hemorrhage) in an 81-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) (batch nos. 032M20A and 010M208) for COVID-19 vaccination. The occurrence of additional non-serious events is detailed below.     The patient's past medical history included Prostate cancer, Subarachnoid hemorrhage in July 2017, COVID-19 (hospitalized and discharged on 06 Jan 2021 and tested negative on 07 Jan 2021) in December 2020, Cerebral amyloid angiopathy and TIA. Previously administered products included for COVID-19: Decadron and Remdesivir. Past adverse reactions to the above products included No adverse reaction with Decadron and Remdesivir. Concurrent medical conditions included Allergy to animal dander (cat dander), Drug allergy (ace inhibitors), Cerebrovascular accident, Thyroid disorder, Benign prostatic hyperplasia, Hyperlipidemia, Dementia, Hypertension and Obstructive sleep apnea syndrome. Concomitant products included ATORVASTATIN CALCIUM (LIPITOR), DONEPEZIL HYDROCHLORIDE (ARICEPT), LEVETIRACETAM (KEPPRA [LEVETIRACETAM]), QUETIAPINE FUMARATE (SEROQUEL) and TAMSULOSIN HYDROCHLORIDE (FLOMAX [TAMSULOSIN HYDROCHLORIDE]) for an unknown indication.   On 01-Feb-2021, the patient received first dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) 1 dosage form. On 12-Mar-2021, received second dose of mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular) dosage was changed to 1 dosage form. On 18-May-2021, the patient experienced SUBARACHNOID HAEMORRHAGE (Small amount of bilateral subarachnoid hemorrhage) (seriousness criteria hospitalization and medically significant), DYSARTHRIA (speech was a little bit thick/ speech is a little bit slurred), TONGUE DISORDER (Tongue has been thick) and GAIT DISTURBANCE (Gait was slow with a shuffling gait). 18-May-2021, the patient experienced FATIGUE (More tired). On an unknown date, the patient experienced CONFUSIONAL STATE (confusion). The patient was hospitalized for 3 days until 20-May-2021 due to SUBARACHNOID HAEMORRHAGE. The patient was treated with ASPIRIN [ACETYLSALICYLIC ACID] at a dose of UNK dosage form and ACETYLSALICYLIC ACID (BABY ASPIRIN) ongoing since an unknown date at a dose of UNK dosage form. On 20-May-2021, SUBARACHNOID HAEMORRHAGE (Small amount of bilateral subarachnoid hemorrhage), DYSARTHRIA (speech was a little bit thick/ speech is a little bit slurred), TONGUE DISORDER (Tongue has been thick) and GAIT DISTURBANCE (Gait was slow with a shuffling gait) had resolved. At the time of the report, CONFUSIONAL STATE (confusion) and FATIGUE (More tired) outcome was unknown.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): In May 2021, Chest X-ray: (Negative) negative. In May 2021, Computerised tomogram head: showed small amount of bilateral subarachnoid hemorrhage and stable. In May 2021, Fibrin D dimer: 1787. In May 2021, Magnetic resonance imaging: normal with no acute abnormal seen. In May 2021, SARS-CoV-2 test: (Positive) positive.     For mRNA-1273 (Moderna COVID-19 Vaccine) (Intramuscular), the reporter did not provide any causality assessments.   Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.   Most recent FOLLOW-UP information incorporated above includes: On 23-May-2021: Upon internal review on 16-SEP-2022 non-significant correction was performed to update the case received from field.; Sender's Comments: Based on the current available information and temporal association between the use of the product and the start date of the events, a causal relationship cannot be excluded.