Pathology Of The Nervous System

Hydrocephalus is caused by the obstruction of cerebrospinal fluid (CSF) flow or the blockage of CSF resorption. This can occur when there is a blockage or narrowing of the passages through which CSF flows, such as the cerebral aqueduct or the foramina of Magendie and Luschka. It can also be caused by a malfunction in the absorption of CSF by the arachnoid granulations. These obstructions or blockages lead to an accumulation of CSF in the ventricles of the brain, causing increased pressure and enlargement of the ventricles, which is characteristic of hydrocephalus.

Parkinson's disease is characterized by a decreased number of dopaminergic neurons in the substantia nigra. Dopaminergic neurons are responsible for producing dopamine, a neurotransmitter that plays a crucial role in regulating movement. The loss of these neurons leads to a deficiency of dopamine in the brain, resulting in the motor symptoms associated with Parkinson's disease, such as tremors, rigidity, and bradykinesia. Other options mentioned in the question, such as IgG composed of oligoclonal bands, deposition of amyloid in neurotic plaques, and atrophy in the caudate and putamen, are not characteristic findings of Parkinson's disease.

Viral encephalitis is characterized by the presence of widespread lymphocytic infiltrates. This means that immune cells called lymphocytes infiltrate various areas of the brain, indicating an inflammatory response to a viral infection. This is a characteristic feature of viral encephalitis and helps differentiate it from other types of encephalitis, such as autoimmune or bacterial encephalitis. Therefore, the statement is true.

Encephalitis is inflammation of the brain parenchyma, which refers to the functional tissue of the brain. This inflammation can be caused by various factors such as viral or bacterial infections, autoimmune disorders, or exposure to certain toxins. It leads to symptoms such as fever, headache, confusion, and neurological deficits. Obstruction of CSF or blockage of CSF resorption, incomplete closure of the fetal neural tube, and lymphocytic exudate in the subarachnoid space are not direct causes of encephalitis.

Meningioma is a tumor that arises from the meninges, the protective covering of the brain and spinal cord. It is generally slow-growing and benign, meaning it is less likely to spread to other parts of the body. Due to its slow growth and limited invasiveness, meningioma tends to have a good prognosis, with a higher chance of successful treatment and long-term survival. On the other hand, medulloblastoma is a malignant tumor that originates in the cerebellum, and it is known for its aggressive behavior and tendency to spread. Therefore, medulloblastoma has a poor prognosis compared to meningioma.

Huntington's disease is characterized by atrophy in the caudate and putamen. This means that these regions of the brain experience a loss of neurons and shrinkage. This atrophy is a key feature of Huntington's and is responsible for the motor, cognitive, and psychiatric symptoms associated with the disease. Other options mentioned in the question, such as IgG composed of oligoclonal bands and deposition of amyloid, are not specific to Huntington's and are associated with other conditions. Similarly, the decreased number of dopaminergic neurons in the substantia nigra is characteristic of Parkinson's disease, not Huntington's.

Alzheimer's disease is characterized by the deposition of amyloid plaques in the walls of cerebral vessels. These plaques are composed of abnormal protein fragments called beta-amyloid. This deposition leads to the formation of neurotic plaques, which are a hallmark pathological feature of Alzheimer's disease. Other characteristics of Alzheimer's include neurofibrillary tangles, neuronal loss, and brain atrophy, but the specific deposition of amyloid in neurotic plaques is the most defining characteristic.

Intracerebral hemorrhage refers to bleeding within the brain tissue itself. It is commonly seen in hematologic diseases like leukemia, where the abnormal blood cells can cause damage to the blood vessels in the brain. Nontraumatic forms of intracerebral hemorrhage can also occur, such as in cases of stroke. This type of hemorrhage is different from epidural hematoma, subdural hematoma, and subarachnoid hemorrhage, which involve bleeding in other areas of the brain or surrounding membranes.

A subdural hematoma is a type of hemorrhage that occurs when there is bleeding between the dura mater (the outermost layer of the meninges) and the arachnoid mater (the middle layer of the meninges) in the brain. This type of hemorrhage is typically caused by ruptured bleeding veins, which can occur after sudden movement of the brain in one direction and the dura in another, often from blunt trauma. This can happen in situations such as boxing or falling out of bed. Therefore, the given answer of subdural hematoma is the most appropriate choice based on the explanation provided.

Intellect stays normal, speech becomes slurred

A subarachnoid hemorrhage is a type of hemorrhage that occurs when there is bleeding between the brain and the thin tissues that cover it (the arachnoid membrane). In this case, the hemorrhage is caused by the rupture of congenital (berry) aneurysms, which are abnormal bulges in blood vessels in the brain. Traumatic contusion, or a bruise on the brain caused by a head injury, can also lead to the rupture of these aneurysms and subsequent subarachnoid hemorrhage.

Dysraphic disorder is caused by incomplete closure of the fetal neural tube. This refers to a condition where the neural tube, which forms the brain and spinal cord, does not fully close during embryonic development. This incomplete closure can lead to various abnormalities and malformations in the central nervous system, such as spina bifida.

Lewy bodies and melanin rich neurons are associated with Parkinson's disease. Lewy bodies are abnormal protein deposits that develop in nerve cells in the brain, particularly in areas that control movement. These deposits disrupt the normal functioning of these cells, leading to symptoms such as tremors, stiffness, and difficulty with balance and coordination. Melanin rich neurons, which produce the pigment melanin, are also affected in Parkinson's disease. This neurodegenerative disorder primarily affects the motor system and is characterized by the progressive loss of dopamine-producing cells in the brain.

Viral meningitis is caused by the presence of lymphocytic exudate in the subarachnoid space. The subarachnoid space is the area between the arachnoid mater and the pia mater, which are the layers that cover the brain and spinal cord. In viral meningitis, the virus causes inflammation in this space, leading to the accumulation of lymphocytes, which are a type of white blood cell. This accumulation of lymphocytes in the subarachnoid space is what causes the characteristic symptoms of viral meningitis, such as headache, fever, and neck stiffness.

An epidural hematoma is a type of hemorrhage that occurs when the middle meningeal artery ruptures, usually due to tearing of a bone spicule. This results in bleeding between the dura mater and the skull, creating a hematoma. The other options, subdural hematoma, subarachnoid hemorrhage, and intracerebral hemorrhage, involve bleeding in different areas of the brain and are not specifically associated with a rupture of the middle meningeal artery.

IgG composed of oligoclonal bands characterizes multiple sclerosis (MS). Oligoclonal bands are abnormal bands of immunoglobulins that can be detected in the cerebrospinal fluid (CSF) of individuals with MS. These bands represent the production of antibodies by plasma cells within the central nervous system, indicating an immune response specific to the disease. The presence of oligoclonal bands in the CSF is a diagnostic marker for MS and is seen in the majority of patients with the disease.

The correct answer is Breast, Lung, Melanoma. These three types of cancer are known to have a higher likelihood of spreading to the brain compared to other types. Breast cancer can metastasize to the brain through the bloodstream or lymphatic system. Lung cancer often spreads to the brain through the bloodstream as well. Melanoma, a type of skin cancer, has a high tendency to metastasize to various organs including the brain. Therefore, these three sites are commonly associated with brain metastases.

Astrocytomas are solid in adults and cystic in children. This means that in adults, astrocytomas typically present as solid masses in the cerebral region of the brain, while in children, they are more likely to be cystic masses found in the cerebellar region.

The statement is true. CNS neoplasms can be classified as primary or metastatic. Primary neoplasms originate within the CNS, while metastatic neoplasms spread to the CNS from other parts of the body. It is true that 50% of CNS neoplasms are primary and 50% are metastatic. However, malignant tumors in the CNS do not typically metastasize to other parts of the body, unlike malignant tumors in other organs. Therefore, the statement is true.

In multiple sclerosis (MS), early lesions are associated with the presence of lymphocytes and macrophages. These immune cells infiltrate the central nervous system and cause inflammation. As the disease progresses, late lesions develop, and these also show the presence of lymphocytes and macrophages. Therefore, both early and late lesions in MS are associated with lymphocytes and macrophages. There is no mention of astrocytes in the question, so it is not clear whether they are associated with early or late lesions.

Cerebral abscesses, which are localized collections of pus in the brain, can indeed be caused by various microorganisms. While bacterial infections are the most common culprits, viruses can also lead to their development. Other potential causes include fungi and parasites. These infections often result from the spread of infection from other areas of the body, such as the ears, sinuses, or lungs, or can occur following trauma or surgery to the head. The resulting inflammation and immune response contribute to the formation of the abscess. Sources and related content

The first symptoms of Huntington's disease typically manifest during midlife, which refers to the middle years of a person's life. This implies that individuals do not experience any signs or symptoms of the disease before reaching this stage. Additionally, the answer suggests that most individuals affected by Huntington's become incapacitated between the ages of 50 and 60.

Astrocytic gliomas account for 80% of all gliomas. Gliomas are tumors that originate in the glial cells of the brain or spinal cord. Astrocytic gliomas specifically arise from astrocytes, a type of glial cell. Therefore, it can be concluded that the majority of gliomas are astrocytic or astrocytic gliomas.