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Pathology - Neurofibromatosis
Autosomal dominant disorder resulting from a mutation in the neurofibromatosis type 1 (NF1) gene, a tumor suppressor gene situated on chromosome 17.
Pathology
Neurofibroma is a type of tumor made up of spindle cells that can be found in the dermis, peripheral nerves, or major nerve trunks. Cutaneous neurofibromas appear as skin nodules and may lead to darkening of the skin above them.
Clinical Neurofibromas can result in neurological symptoms depending on their position on various nerves, for example, gliomas on the optic nerve might cause vision abnormalities. Patients may have Lisch nodules (pigmented nodules of the iris) or Cafe-au-lait spots (pigmented macules on the skin) upon examination. Bending and tilting of long bones such as the tibia or radial bone, or the development of scoliosis, can lead to symptoms resembling arthritis. Hypertension is a prevalent condition.
Therapy
Surgery is performed to remove neurofibromas if they are causing disfigurement or neurological problems. Hypertension is treated if necessary.
Neurofibromatosis type 2 is an autosomal dominant disorder caused by a mutation in the NF2 gene on chromosome 22. It is less common than neurofibromatosis type 1 and is characterized by bilateral auditory schwannomas, numerous meningiomas, and other neoplasms.
Autosomal dominant disorder resulting from a mutation in the neurofibromatosis type 1 (NF1) gene, a tumor suppressor gene situated on chromosome 17.
Pathology
Neurofibroma is a type of tumor made up of spindle cells that can be found in the dermis, peripheral nerves, or major nerve trunks. Cutaneous neurofibromas appear as skin nodules and may lead to darkening of the skin above them.
Clinical Neurofibromas can result in neurological symptoms depending on their position on various nerves, for example, gliomas on the optic nerve might cause vision abnormalities. Patients may have Lisch nodules (pigmented nodules of the iris) or Cafe-au-lait spots (pigmented macules on the skin) upon examination. Bending and tilting of long bones such as the tibia or radial bone, or the development of scoliosis, can lead to symptoms resembling arthritis. Hypertension is a prevalent condition.
Therapy
Surgery is performed to remove neurofibromas if they are causing disfigurement or neurological problems. Hypertension is treated if necessary.
Neurofibromatosis type 2 is an autosomal dominant disorder caused by a mutation in the NF2 gene on chromosome 22. It is less common than neurofibromatosis type 1 and is characterized by bilateral auditory schwannomas, numerous meningiomas, and other neoplasms.
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Pathology - Osteogenesis Imperfecta
Inherited mutations lead to a lack of type 1 collagen synthesis, affecting bone, teeth, ears, eyes, and skin. Inheritance is primarily autosomal dominant, although there are occasional instances of autosomal recessive inheritance. There are four varieties, with type II being the most severe and typically leading to neonatal mortality.
Bone shows cortical thinning with trabecular thinning resembling osteoporosis.
Multiple fractures resulting from minor trauma; blue sclerae caused by the transparency of connective tissue over choroids; hearing loss due to aberrant middle ear bones; dental abnormalities.
Therapy
Utilizing pneumatic bracing to prevent trauma.
The prognosis varies depending on the type of disease and might range from mortality in infancy to a typical lifespan.
Achondroplasia is the outcome of an autosomal dominant mutation in the fibroblast growth factor receptor 3 (FGFR3) gene on chromosome 4, leading to irregularities in cartilage calcification and restructuring. It presents clinically as dwarfism, with small limbs and a normal trunk, and is defined by narrow epiphyseal plates and short, thick bones.
Inherited mutations lead to a lack of type 1 collagen synthesis, affecting bone, teeth, ears, eyes, and skin. Inheritance is primarily autosomal dominant, although there are occasional instances of autosomal recessive inheritance. There are four varieties, with type II being the most severe and typically leading to neonatal mortality.
Bone shows cortical thinning with trabecular thinning resembling osteoporosis.
Multiple fractures resulting from minor trauma; blue sclerae caused by the transparency of connective tissue over choroids; hearing loss due to aberrant middle ear bones; dental abnormalities.
Therapy
Utilizing pneumatic bracing to prevent trauma.
The prognosis varies depending on the type of disease and might range from mortality in infancy to a typical lifespan.
Achondroplasia is the outcome of an autosomal dominant mutation in the fibroblast growth factor receptor 3 (FGFR3) gene on chromosome 4, leading to irregularities in cartilage calcification and restructuring. It presents clinically as dwarfism, with small limbs and a normal trunk, and is defined by narrow epiphyseal plates and short, thick bones.
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Pathology - Osteopetrosis
abnormal bone resorption as a result of osteoclast activity dysfunction.
There are other varieties, such as a less severe autosomal dominant form and a deadly autosomal recessive variety.
Pathology
Gross: Dense, thick bones; widened ends of bones (Erlenmeyer flask appearance).
Microscopic: Absence of hematopoietic marrow or trabeculae; persistence of primary spongiosa, calcified cartilage generated during endochondral bone formation.
Clinical Signs and Symptoms
Multiple fractures; infections; hepatosplenomegaly (from extramedullary hematopoiesis); cranial nerve palsies (blindness, deafness, facial paralysis); and various neuropathies (from nerve compression brought on by restricted neural foramina).
Treatment
corticosteroids and bone marrow transplantation as treatments.
A condition known as McCune-Albright syndrome affects young girls. Cafe-au-lait spots, small stature, early puberty (or other endocrine hyperfunctions like acromegaly or hyperthyroidism), and polyostotic fibrous dysplasia (fibrous replacement of medullary bone in various sites) are some of its manifestations.
abnormal bone resorption as a result of osteoclast activity dysfunction.
There are other varieties, such as a less severe autosomal dominant form and a deadly autosomal recessive variety.
Pathology
Gross: Dense, thick bones; widened ends of bones (Erlenmeyer flask appearance).
Microscopic: Absence of hematopoietic marrow or trabeculae; persistence of primary spongiosa, calcified cartilage generated during endochondral bone formation.
Clinical Signs and Symptoms
Multiple fractures; infections; hepatosplenomegaly (from extramedullary hematopoiesis); cranial nerve palsies (blindness, deafness, facial paralysis); and various neuropathies (from nerve compression brought on by restricted neural foramina).
Treatment
corticosteroids and bone marrow transplantation as treatments.
A condition known as McCune-Albright syndrome affects young girls. Cafe-au-lait spots, small stature, early puberty (or other endocrine hyperfunctions like acromegaly or hyperthyroidism), and polyostotic fibrous dysplasia (fibrous replacement of medullary bone in various sites) are some of its manifestations.
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Pathology - Epidural Hematoma and Subdural Hematoma
Epidural hematoma is typically the result of the rupture of the middle meningeal artery, middle meningeal vein, or dural sinus, generally due to a skull fracture.
Subdural hematoma is the result of the rupture of bridge veins situated between the cerebrum and venous sinuses in the dura, typically caused by head trauma.
Epidural hematoma: Blood buildup between the dura mater and the skull causing compression on the brain.
Subdural hematoma is the accumulation of blood between the dura mater and arachnoid membrane. The bleeding is self-limited, but the hematoma might expand due to osmotic water movement. Resolution may occur with the formation of granulation tissue, leading to a chronic subdural hematoma.
Epidural anesthesia leads to unconsciousness, a clear period of awareness, headache, changes in mental function, seizures, specific neurological impairments, and ultimately a state of unconsciousness. Imaging findings: Head CT reveals a biconcave disk that does not extend across suture lines.
Subdural symptoms include headache, altered mental status, and evidence of cerebral compression. These clinical manifestations develop gradually, typically emerging hours to weeks after the injury. Imaging: Head CT reveals a crescent-shaped disk that extends across suture lines.
Treatment.
Surgically draining blood and correcting coagulopathy.
Epidural hematoma is typically the result of the rupture of the middle meningeal artery, middle meningeal vein, or dural sinus, generally due to a skull fracture.
Subdural hematoma is the result of the rupture of bridge veins situated between the cerebrum and venous sinuses in the dura, typically caused by head trauma.
Epidural hematoma: Blood buildup between the dura mater and the skull causing compression on the brain.
Subdural hematoma is the accumulation of blood between the dura mater and arachnoid membrane. The bleeding is self-limited, but the hematoma might expand due to osmotic water movement. Resolution may occur with the formation of granulation tissue, leading to a chronic subdural hematoma.
Epidural anesthesia leads to unconsciousness, a clear period of awareness, headache, changes in mental function, seizures, specific neurological impairments, and ultimately a state of unconsciousness. Imaging findings: Head CT reveals a biconcave disk that does not extend across suture lines.
Subdural symptoms include headache, altered mental status, and evidence of cerebral compression. These clinical manifestations develop gradually, typically emerging hours to weeks after the injury. Imaging: Head CT reveals a crescent-shaped disk that extends across suture lines.
Treatment.
Surgically draining blood and correcting coagulopathy.
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Pathology - Hydrocephalus
Hydrocephalus is caused by the buildup of excess cerebrospinal fluid in the skull, which can be due to blockages in CSF flow caused by tumors or inflammation, or by the excessive production of CSF by tumors in the choroid plexus.
Pathology: Ventricular dilation observed on gross examination.
There are four types of hydrocephalus: (1) Internal hydrocephalus: excess cerebrospinal fluid (CSF) is found exclusively in the ventricular system; (2) External hydrocephalus: excess CSF is found only in the subarachnoid space; (3) Communicating hydrocephalus: CSF flows freely between the ventricles and subarachnoid space; (4) Noncommunicating hydrocephalus: there is an obstruction in the flow of CSF between the ventricles and subarachnoid space.
Clinical Symptoms and Signs
May manifest as skull enlargement in adults, seizures, headaches, vision problems, nausea, vomiting, and other symptoms of elevated intracranial pressure.
Therapy
Placement of ventriculoperitoneal shunt; extraction of blockage or choroid plexus tumor.
Hydrocephalus ex vacuo is the enlargement of the brain's ventricles due to a higher volume of cerebrospinal fluid caused by a reduction in brain tissue, typically due to conditions like infarction or Alzheimer's disease.
Normal-pressure hydrocephalus is a clinical condition identified by the presence of magnetic gait, urine incontinence, and dementia. Brain imaging shows ventricular enlargement. A lumbar puncture shows a normal opening pressure and offers both diagnostic and therapeutic advantages, as symptoms improve when cerebrospinal fluid is removed during the procedure. The definitive treatment involves the insertion of a ventriculoperitoneal shunt.
Hydrocephalus is caused by the buildup of excess cerebrospinal fluid in the skull, which can be due to blockages in CSF flow caused by tumors or inflammation, or by the excessive production of CSF by tumors in the choroid plexus.
Pathology: Ventricular dilation observed on gross examination.
There are four types of hydrocephalus: (1) Internal hydrocephalus: excess cerebrospinal fluid (CSF) is found exclusively in the ventricular system; (2) External hydrocephalus: excess CSF is found only in the subarachnoid space; (3) Communicating hydrocephalus: CSF flows freely between the ventricles and subarachnoid space; (4) Noncommunicating hydrocephalus: there is an obstruction in the flow of CSF between the ventricles and subarachnoid space.
Clinical Symptoms and Signs
May manifest as skull enlargement in adults, seizures, headaches, vision problems, nausea, vomiting, and other symptoms of elevated intracranial pressure.
Therapy
Placement of ventriculoperitoneal shunt; extraction of blockage or choroid plexus tumor.
Hydrocephalus ex vacuo is the enlargement of the brain's ventricles due to a higher volume of cerebrospinal fluid caused by a reduction in brain tissue, typically due to conditions like infarction or Alzheimer's disease.
Normal-pressure hydrocephalus is a clinical condition identified by the presence of magnetic gait, urine incontinence, and dementia. Brain imaging shows ventricular enlargement. A lumbar puncture shows a normal opening pressure and offers both diagnostic and therapeutic advantages, as symptoms improve when cerebrospinal fluid is removed during the procedure. The definitive treatment involves the insertion of a ventriculoperitoneal shunt.
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Pathology - Syringomyelia
Commonly linked to Arnold-Chiari malformation or thoracic kyphoscoliosis; can also result from intraspinal neoplasms or trauma.
A fluid-filled hollow typically forms in the spinal cord, often extending from the central canal, mainly in the cervical area (most commonly C7-T1). This leads to the loss of nearby gray and white matter, including the crossing fibers of the spinothalamic tract, resulting in reactive gliosis.
Loss of pain and temperature feeling in the upper extremities typically accompanied by intact touch and proprioception; may later extend to affect motor and other sensory pathways.
Treatment
Surgical drainage of a cavity.
Commonly linked to Arnold-Chiari malformation or thoracic kyphoscoliosis; can also result from intraspinal neoplasms or trauma.
A fluid-filled hollow typically forms in the spinal cord, often extending from the central canal, mainly in the cervical area (most commonly C7-T1). This leads to the loss of nearby gray and white matter, including the crossing fibers of the spinothalamic tract, resulting in reactive gliosis.
Loss of pain and temperature feeling in the upper extremities typically accompanied by intact touch and proprioception; may later extend to affect motor and other sensory pathways.
Treatment
Surgical drainage of a cavity.
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Pathology - Myasthenia Gravis
Resulting from antibodies targeting the acetylcholine receptors at the neuromuscular junction.
Linked to thymoma, thymic hyperplasia, or other autoimmune diseases.
Most commonly occurs in women under 40 years old.
Neuromuscular junction is affected by a decrease in acetylcholine receptors and the presence of immune complexes and complement factors.
Pathophysiology: Antibodies cause degradation of acetylcholine receptors, resulting in a near-complete inhibition of synaptic transmission.
Initial symptoms often include ptosis or diplopia caused by extraocular muscle weakness, which can progress with exhaustion. Other often affected muscles, such as those in the extremities or face, may also experience easy tiredness.
Diagnosis was verified through improvement following the injection of a short-acting anticholinesterase (edrophonium).
Laboratory results: Presence of antibodies targeting cholinergic receptors.
Treatment includes anticholinesterase medications such as pyridostigmine, thymectomy, immunosuppression, and plasmapheresis in cases of severe flare.
Resulting from antibodies targeting the acetylcholine receptors at the neuromuscular junction.
Linked to thymoma, thymic hyperplasia, or other autoimmune diseases.
Most commonly occurs in women under 40 years old.
Neuromuscular junction is affected by a decrease in acetylcholine receptors and the presence of immune complexes and complement factors.
Pathophysiology: Antibodies cause degradation of acetylcholine receptors, resulting in a near-complete inhibition of synaptic transmission.
Initial symptoms often include ptosis or diplopia caused by extraocular muscle weakness, which can progress with exhaustion. Other often affected muscles, such as those in the extremities or face, may also experience easy tiredness.
Diagnosis was verified through improvement following the injection of a short-acting anticholinesterase (edrophonium).
Laboratory results: Presence of antibodies targeting cholinergic receptors.
Treatment includes anticholinesterase medications such as pyridostigmine, thymectomy, immunosuppression, and plasmapheresis in cases of severe flare.
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Pathology-Seizures
Seizures can be caused by toxins (such as drugs or alcohol withdrawal), intracranial issues (including stroke, bleeding, tumors, infections, or degenerative disorders), metabolic imbalances (such as low sodium or low blood sugar), or epilepsy (a condition characterized by recurring seizures).
Neurologic symptoms occur due to abnormal discharge of central nervous system neurons.
The seizure is typically preceded by an aura, which might involve unusual smells or visual disturbances, and is then followed by the seizure itself. There is generally a postictal interval after the seizure, characterized by minutes to hours of bewilderment and tiredness.
Seizures can be categorized as either partial, affecting a specific area of the brain, or generalized. Simple partial seizures do not result in a loss of consciousness and can affect motor, sensory, or autonomic functions of the brain. (2) Complex partial seizures are similar to simple partial seizures, but they involve compromised consciousness. (3) Tonic-clonic (grand mal): muscular contractions alternating with relaxation;
(4) Absence: temporary loss of awareness without losing muscle control; (5) Myoclonic: abrupt, short muscle contractions.
Therapy
Anticonvulsant medications; address root issues.
Status epilepticus is defined as a prolonged tonic-clonic seizure lasting more than 30 minutes.
Possible complications involve anoxic brain damage and lactic acidosis.
Seizures can be caused by toxins (such as drugs or alcohol withdrawal), intracranial issues (including stroke, bleeding, tumors, infections, or degenerative disorders), metabolic imbalances (such as low sodium or low blood sugar), or epilepsy (a condition characterized by recurring seizures).
Neurologic symptoms occur due to abnormal discharge of central nervous system neurons.
The seizure is typically preceded by an aura, which might involve unusual smells or visual disturbances, and is then followed by the seizure itself. There is generally a postictal interval after the seizure, characterized by minutes to hours of bewilderment and tiredness.
Seizures can be categorized as either partial, affecting a specific area of the brain, or generalized. Simple partial seizures do not result in a loss of consciousness and can affect motor, sensory, or autonomic functions of the brain. (2) Complex partial seizures are similar to simple partial seizures, but they involve compromised consciousness. (3) Tonic-clonic (grand mal): muscular contractions alternating with relaxation;
(4) Absence: temporary loss of awareness without losing muscle control; (5) Myoclonic: abrupt, short muscle contractions.
Therapy
Anticonvulsant medications; address root issues.
Status epilepticus is defined as a prolonged tonic-clonic seizure lasting more than 30 minutes.
Possible complications involve anoxic brain damage and lactic acidosis.
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Pathology-Meningitis
Pyogenic meningitis is caused by different bacteria depending on the age group: Group B streptococci, Escherichia coli, and Listeria in neonates and infants; Haemophilus influenzae and Neisseria meningitidis in children and young adults; and pneumococcus, Listeria, and gram-negative rods in older individuals.
Causes of viral meningitis include HSY virus, Coxsackievirus, echoviruses, and arboviruses.
Pyogenic meningitis is characterized by a purulent discharge in the leptomeninges, engorged meningeal arteries, and the presence of neutrophils in the subarachnoid space.
Viral meningitis may show either no abnormalities or a slight lymphocytic infiltration in the subarachnoid space, with moderate edema perhaps occurring.
Pyogenic meningitis presents with symptoms such as headache, photophobia, neck stiffness, fever, and altered mental status.
Laboratory results indicate that the cerebrospinal fluid obtained from a lumbar puncture appears cloudy, contains neutrophils, has elevated protein levels, reduced glucose levels, and demonstrates increased opening pressure.
Symptoms of viral meningitis include headache, photophobia, neck stiffness, fever, and altered mental status. Lab results: Lumbar puncture indicates an increase in lymphocytes, slightly raised protein levels, and normal glucose levels.
Pyogenic meningitis is treated with antibiotics and supportive care. Steroids may be considered for H influenzae infection.
Viral meningitis is a self-limiting condition. Acyclovir is used for herpes simplex virus (HSY) meningitis.
Viral encephalitis is an infection that affects the brain and/or meninges.
It can be caused by several organisms such as arboviruses, herpes, CMY, rabies, and poliovirus.
Glial nodules, neuronal inclusion bodies, and perivascular mononuclear cell infiltrates are observed histopathologically.
Pyogenic meningitis is caused by different bacteria depending on the age group: Group B streptococci, Escherichia coli, and Listeria in neonates and infants; Haemophilus influenzae and Neisseria meningitidis in children and young adults; and pneumococcus, Listeria, and gram-negative rods in older individuals.
Causes of viral meningitis include HSY virus, Coxsackievirus, echoviruses, and arboviruses.
Pyogenic meningitis is characterized by a purulent discharge in the leptomeninges, engorged meningeal arteries, and the presence of neutrophils in the subarachnoid space.
Viral meningitis may show either no abnormalities or a slight lymphocytic infiltration in the subarachnoid space, with moderate edema perhaps occurring.
Pyogenic meningitis presents with symptoms such as headache, photophobia, neck stiffness, fever, and altered mental status.
Laboratory results indicate that the cerebrospinal fluid obtained from a lumbar puncture appears cloudy, contains neutrophils, has elevated protein levels, reduced glucose levels, and demonstrates increased opening pressure.
Symptoms of viral meningitis include headache, photophobia, neck stiffness, fever, and altered mental status. Lab results: Lumbar puncture indicates an increase in lymphocytes, slightly raised protein levels, and normal glucose levels.
Pyogenic meningitis is treated with antibiotics and supportive care. Steroids may be considered for H influenzae infection.
Viral meningitis is a self-limiting condition. Acyclovir is used for herpes simplex virus (HSY) meningitis.
Viral encephalitis is an infection that affects the brain and/or meninges.
It can be caused by several organisms such as arboviruses, herpes, CMY, rabies, and poliovirus.
Glial nodules, neuronal inclusion bodies, and perivascular mononuclear cell infiltrates are observed histopathologically.
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Pathology- Bell Palsy
The precise cause is uncertain, however it is believed to be related to viral reactivation, particularly by HSV-1 or herpes zoster virus, as well as inflammatory and immunological factors.
Most commonly occurs in adults, diabetics, or during pregnancy.
Study of the disordered physiological processes that cause disease.
Edema and inflammation cause compression of the facial nerve in the temporal bone canal, where the nerve passes through.
Clinical Symptoms and Signs
The sudden onset of paralysis in the upper and lower face, reduced taste sensation, ear pain on the same side, drooling, dry eyes with reduced tear production, and potential corneal injury (infection or ulceration) caused by the inability to fully seal the affected eye.
Therapy
Consider using corticosteroids and antiviral medication (acyclovir) to manage the condition. Additionally, provide eye care by using ocular lubrication to reduce the chances of corneal damage.
The prognosis is favorable, with 80%-90% of patients achieving full recovery within 6-12 weeks.
The precise cause is uncertain, however it is believed to be related to viral reactivation, particularly by HSV-1 or herpes zoster virus, as well as inflammatory and immunological factors.
Most commonly occurs in adults, diabetics, or during pregnancy.
Study of the disordered physiological processes that cause disease.
Edema and inflammation cause compression of the facial nerve in the temporal bone canal, where the nerve passes through.
Clinical Symptoms and Signs
The sudden onset of paralysis in the upper and lower face, reduced taste sensation, ear pain on the same side, drooling, dry eyes with reduced tear production, and potential corneal injury (infection or ulceration) caused by the inability to fully seal the affected eye.
Therapy
Consider using corticosteroids and antiviral medication (acyclovir) to manage the condition. Additionally, provide eye care by using ocular lubrication to reduce the chances of corneal damage.
The prognosis is favorable, with 80%-90% of patients achieving full recovery within 6-12 weeks.
