Although vertigo is one of the most common complaints, intracranial malignant tumors rarely cause sudden asymmetry between the tone of the vestibular peripheries masquerading as a peripheral-like disorder. Here we report a case of simultaneous temporal bone infiltrating macro-metastasis and disseminated multi-organ micro-metastases presenting as acute unilateral vestibular syndrome, due to the reawakening of a primary gastric signet ring cell carcinoma. Purpose – Our objective was to identify those pathophysiological steps that may explain the complex process of tumor reawakening, dissemination. The possible causes of vestibular asymmetry were also traced. A 56-year-old male patient’s interdisciplinary medical data had been retrospectively analyzed. Original clinical and pathological results have been collected and thoroughly reevaluated, then new histological staining and immunohistochemistry methods have been added to the diagnostic pool. During the autopsy the cerebrum and cerebellum was edematous. The apex of the left petrous bone was infiltrated and destructed by a tumor mass of 2x2 cm in size. Histological reexamination of the original gastric resection specimen slides revealed focal submucosal tumorous infiltration with a vascular invasion. By immunohistochemistry mainly single infiltrating tumor cells were observed with Cytokeratin 7 and Vimentin positivity and partial loss of E-cadherin staining. The subsequent histological examination of necropsy tissue specimens confirmed the disseminated, multi-organ microscopic tumorous invasion. Discussion – It has been recently reported that the expression of Vimentin and the loss of E-cadherin is significantly associated with advanced stage, lymph node metastasis, vascular and neural invasion and undifferentiated type with p<0.05 significance. As our patient was middle aged and had no immune-deficiency, the promoting factor of the reawakening of the primary GC malignant disease after a 9-year-long period of dormancy remained undiscovered. The organ-specific tropism explained by the “seed and soil” theory was unexpected, due to rare occurrence of gastric cancer to metastasize in the meninges given that only a minority of these cells would be capable of crossing the blood brain barrier. Patients with past malignancies and new onset of neurological symptoms should alert the physician to central nervous system involvement, and the appropriate, targeted diagnostic and therapeutic work-up should be established immediately. Targeted staining with specific antibodies is recommended. Recent studies on cell lines indicate that metformin strongly inhibits epithelial-mesenchymal transition of gastric cancer cells. Therefore, further studies need to be performed on cases positive for epithelial-mesenchymal transition.

Sandhoff disease is a rare type of hereditary (autosomal recessive) GM2-gangliosidosis, which is caused by mutation of the HEXB gene. Disruption of the β subunit of the hexosaminidase (Hex) enzyme affects the function of both the Hex-A and Hex-B isoforms. The severity and the age of onset of the disease (infantile or classic; juvenile; adult) depends on the residual activity of the enzyme. The late-onset form is characterized by diverse symptomatology, comprising motor neuron disease, ataxia, tremor, dystonia, psychiatric symptoms and neuropathy. A 36-year-old female patient has been presenting progressive, symmetrical lower limb weakness for 9 years. Detailed neurological examination revealed mild symmetrical weakness in the hip flexors without the involvement of other muscle groups. The patellar reflex was decreased on both sides. Laboratory tests showed no relevant alteration and routine electroencephalography and brain MRI were normal. Nerve conduction studies and electromyography revealed alterations corresponding to sensory neuropathy. Muscle biopsy demonstrated signs of mild neurogenic lesion. Her younger brother (32-year-old) was observed with similar symptoms. Detailed genetic study detected a known pathogenic missense mutation and a 15,088 base pair long known pathogenic deletion in the HEXB gene (NM_000521.4:c.1417G>A; NM_000521:c.-376-5836_669+1473del; double heterozygous state). Segregation analysis and hexosaminidase enzyme assay of the family further confirmed the diagnosis of late-onset Sandhoff disease. The purpose of this case report is to draw attention to the significance of late-onset Sandhoff disease amongst disorders presenting with proximal predominant symmetric lower limb muscle weakness in adulthood.

Introduction - Coronavirus disease 2019 (COVID-19) is a respiratory infection that has rapidly become a global pandemic and vaccines against SARS-CoV-2 have been developed with great success. In this article, we would like to present a patient who developed Guillain-Barré syndrome (GBS), which is a serious complication after receiving the inactive SARS-CoV-2 vaccine (CoronaVac). Case report – A 76-year-old male patient presented to the emergency department with nine days of progressive limb weakness. Two weeks prior to admission, he received the second dose of CoronaVac vaccine. Motor examination revealed decreased extremity strength with 3/5 in the lower extremities versus 4/5 in the upper extremities. Deep tendon reflexes were absent in all four extremities. Nerve conduction studies showed predominantly reduced amplitude in both motor and sensory nerves, consistent with AMSAN (acute motor and sensory axonal neuropathy). Conclusion - Clinicians should be aware of the neuro­logical complications or other side effects associated with COVID-19 vaccination so that early treatment can be an option.

Vaccines against the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been rapidly developed to prevent coronavirus disease 2019 (COVID-19) pandemic. There is increasing safety concerns regarding COVID-19 vaccines. We report a 78-year old woman who was presented with tetraparesis, paresthesias of bilateral upper extremities, and urinary retention of one-day duration. Three weeks before these symptoms, she was vaccinated with CoronaVAC vaccine (Sinovac Life Sciences, China). Spine magnetic resonance imaging showed longitudinally extensive transverse myelitis (TM) from the C1 to the T3 spinal cord segment. An extensive diagnostic workup was performed to exclude other possible causes of TM. We suggest that longitudinally extensive TM may be associated with COVID-19 vaccination in this case. To the best of our knowledge, this is the first report of longitudinally extensive TM developing after CoronaVac vaccination. Clinicians should be aware of neurological symptoms after vaccination of COVID-19.