Differential Diagnosis in Neurology: Meningitis, TIA, and Dementia

Clinical Scenario

Jack Williams is a septuagenarian male with a history of coronary artery disease and hypertension. He presents with a several-day history of fever, headache, and weakness. His wife states that he seemed confused and she was having difficulty understanding what he was saying to her. His vitals were 103°F temperature, BP 96/52, HR 101 bpm, and RR 20/minute. On exam, his mental status was drowsy and he was oriented only to person. His neurological exam was non-focal.

Three Possible Conditions

Dementia

Dementia is caused by changes or damage in the brain. Some of the common causes of dementia are vascular dementia, Alzheimer's disease, and severe head injury. The pathogenesis of dementia is characterized by increased deficits in memory and thinking (Blaszczyk, 2022). The clinical manifestations include progressive impairments in behavior, thinking, and memory associated with decreased motivation, difficulties with language, and emotional problems.

Transient Ischemic Attack (TIA)

TIA is caused by factors such as hypertension, diabetes, consumption of unhealthy diet, alcoholism, obesity, smoking, age, lack of engagement in physical activities, and psychosocial stress (Panuganti et al., 2023). The condition occurs when the flow of blood to the brain is interrupted due to a blockage of an artery. Clinical manifestations of TIA include confusion, dizziness, problems with walking, trouble in vision, weakness, numbness, and loss of balance.

Coronary Artery Disease (CAD)

The causes of CAD are high cholesterol, high blood pressure, family history of heart disease, obesity, lipid levels, smoking, and diabetes. Atherosclerosis is the major etiopathogenic process that leads to CAD and the progression is related to the interaction between genetic and environmental factors (Shahjehan et al., 2024). Clinical manifestations include fatigue, chest pain, swelling in feet or hands, shortness of breath, and heart palpitations.

Definitive Diagnostic Tests

1. MRI Scan: Confirms dementia diagnosis by examining brain shrinkage in various areas
2. Computerized Tomography (CT): Diagnoses TIA through examination of the brain and neck
3. Electrocardiogram (ECG): Diagnoses coronary artery disease by recording electrical impulses of the heart

Meningitis Risk Assessment

Given the fever, the diagnosis is likely meningitis. The patient's history of coronary artery disease and hypertension increases the risk of meningitis if he also has an infection that can lead to meningitis. Bacterial meningitis can occur as infective endocarditis that affects patients with heart diseases. Infective endocarditis is life-threatening and its symptoms include coma, seizures, neck rigidity, and headache (Gautam et al., 2023).

Hypertension does not directly increase the patient's risk of meningitis, but meningitis increases the risk of infectious hypertension (El-Hajj et al., 2024). Infectious hypertension occurs when the inflammation due to meningitis leads to an imbalance in blood flow, the brain's water content, and cerebrospinal fluid (Kiefer et al., 2020).

References

• Blaszczyk, J. W. (2022). Pathogenesis of dementia. International Journal of Molecular Sciences, 24(1), 543.
• El-Hajj, V. G., et al. (2024). Detection and management of elevated intracranial pressure in bacterial meningitis. Neurocritical Care, 1-16.
• Gautam, S., et al. (2023). Infective endocarditis presenting as meningitis: a case report. Annals of Medicine and Surgery, 85(7), 3638-3641.
• Kiefer, L., et al. (2020). Viral meningitis mimicking benign intracranial hypertension. Interdisciplinary Neurosurgery, 20, 100646.
• Panuganti, K. K., Tadi, P., & Lui, F. (2023). Transient ischemic attack. NCBI.
• Shahjehan, R. D., Sharma, S., & Bhutta, B. S. (2024). Coronary artery disease. StatPearls.