Medical Case Analysis - Cardiovascular and Neurological Symptoms

Which enzyme is associated with pyruvate dehydrogenase in the conversion of pyruvate to acetyl-CoA?

What is the primary central nervous system manifestation of thiamine deficiency?

What combination of symptoms signifies Wernicke-Korsakoff syndrome?

Which part of the brain is primarily noted for atrophy in thiamine deficiency pathologies on MRI?

What must be administered before glucose to patients with suspected thiamine deficiency?

Which metabolic pathway is associated with transketolase and thiamine?

What is the likely diagnosis for the homeless man with a history of alcoholism and the presented symptoms?

Which clinical manifestation is associated with wet beriberi?

What does thiamine act as a cofactor for?

What symptom would not typically indicate vitamin B12 deficiency?

How does dry beriberi primarily present in patients?

What is a notable effect of arsenic poisoning relating to thiamine?

Which enzyme is not associated with thiamine deficiency?

What laboratory finding is most characteristic of vitamin B1 deficiency?

Thiamine Deficiency

A 36-year-old homeless man presents with shortness of breath, tingling and burning in his legs, and decreased sensation in his feet due to thiamine deficiency.
The patient has an extensive history of alcoholism, which can lead to thiamine deficiency.
Physical examination reveals tachycardia, bilateral rales, and bilateral pitting edema.
An x-ray of the chest shows an enlarged cardiac silhouette and bilateral pulmonary congestion.

Beriberi

The patient has symptoms of both wet and dry beriberi.
Wet beriberi presents with high-output congestive heart failure and dilated cardiomyopathy.
Dry beriberi presents with peripheral neuropathy, muscular atrophy, and diminished sensation and reflexes.

Thiamine as a Cofactor

Thiamine is part of thiamine pyrophosphate (TPP), which acts as a cofactor for three enzymes:
- Transketolase (in the hexose monophosphate shunt)
- Pyruvate decarboxylase (in the pyruvate dehydrogenase complex)
- α-ketoglutarate decarboxylase (in the α-ketoglutarate dehydrogenase complex)

Other Pathologies

Wernicke encephalopathy is the central nervous system manifestation of thiamine deficiency.
Wernicke encephalopathy consists of nystagmus, ophthalmoplegia, and cerebellar ataxia.
Wernicke-Korsakoff syndrome is the combination of Wernicke encephalopathy and symptoms of confusion, psychosis, and confabulation.
It is standard practice to give thiamine before glucose to any patient with suspected thiamine deficiency to prevent Wernicke-Korsakoff syndrome.

MRI Findings

Atrophy of the mammillary bodies is the most commonly noted finding.
Degenerative changes may be seen in the cerebellum, brain stem, and diencephalon.

A homeless man presents with shortness of breath, tingling in his legs, and other symptoms. Analyze the physical examination results to diagnose his condition.