Sulci
Present transependymal migration of CSF, especially to the frontal and occipital horns. Edema resolves quickly after ventricular decompression by shunting, within 24 hours Accentuated in normoten-sive hydrocephalus Thin, distended, rounded elevation. Increased forni-cocallosal distance Normal except in Alzheimer's disease Normal except in cere-bellar atrophy Normal or atrophied Normal fornicocallosal distance Markedly enlarged in Alzheimer's disease
Compression within the Spiral Groove of the Humerus
Lesions of the radial nerve occur most commonly in this region. The lesions are usually due to displaced fractures of the humeral shaft after inebriated sleep, during which the arm is allowed to hang off the bed or bench Saturday night palsy , during general anesthesia, or from callus formation due to an old humeral fracture. There may be a familial history, or underlying diseases such as alcoholism, lead and arsenic poisoning, diabetes mellitus, polyarteritis nodosa, serum sickness, or...
Petrous ridge or apex
Inflammatory Acute petrositis is a nondestructive inflammatory con dition, affecting only 30-50 of patients with an aerated petrous apex, and is characterized by irregular spotty opacifications scattered throughout the petrous pyramid. Spread of the inflammation may lead to osteomyelitis and abscess formation in the petrous pyramid. The involvement of the surrounding tissues causes irritation of cranial nerve V, with periorbital pain, and sixth nerve palsy, causing diplopia and otorrhea, e.g.,...
Internal auditory canal
Represents about 8 of all intracranial tumors. It arises from the Schwann cells which invest the eighth nerve as it enters the internal auditory canal. Ninety-five percent of these lesions originate within the auditory canal, and the other 5 arise from the nerve at its cerebellopontine angle course, proximal to the canal. Often bilateral in neurofibromatosis. Most acoustic neuromas arise from the superior vestibular branch of the eighth cranial nerve. The most noticeable radiographic change...
Meralgia Paresthetica BernhardtRoth syndrome
The lateral cutaneous nerve is a purely sensory branch arising from the lumbar plexus L2-L3 . It passes obliquely across the iliac muscle, and enters the thigh under the lateral part of the inguinal ligament. It supplies the skin over the anterolateral aspect of the thigh. Meralgia paresthetica is a condition caused by entrapment of this nerve as it passes through the opening between the inguinal ligament and its attachment 1 - 2 cm medial to the anterior superior iliac spine. Numbness is the...
Ulnar Entrapment at the Elbow Cubital Tunnel
This results from entrapment of the ulnar nerve as it enters the forearm through the narrow opening the cubital tunnel formed by the medial humeral epicondyle, the medial collateral ligament of the joint, and the firm aponeurotic band, to which the flexor carpi ulnaris is attached. Elbow flexion reduces the size of the opening under the aponeurotic band, while extension widens it. Tardy ulnar palsy results from narrowing of the cubital tunnel secondary to an elbow fracture or in osteoarthritis,...
Cauda Equina Mass Lesions
Compression of the lumbar and sacral roots below the L3 vertebral level Characteristics of the cauda equina syndrome - Early bilateral and asymmetrical radicular pain in the distribution of the lumbosacral roots, increased by the Valsalva maneuver - Absence of the Achilles reflexes S1 -2 roots the patellar reflexes L2-4 roots have a variable response - Flaccid, hypotonic, areflexic paralysis affecting the gluteal muscles, posterior thigh muscles, and the anterolateral muscles of the leg and...
Cervicocephalic Syndrome Versus Migraine Versus Mnires Disease
Cervicocephalic Migraine M ni re's dis Cervicocephalic Migraine M ni re's dis Differentiation between Spasticity and Rigidity
Cerebellopontine angle
the basal nucleus of Meynert, the pallidum, subthalamic nucleus, substantia nigra, locus ceruleus, and superior colliculi patients have ophthalmoparesis of downward gaze, Parkinsonism, pseudobulbar palsy, and frontal lobe signs Paramedian and basal infarction e.g., Millard-Gubler syndrome, Gasperini's syndrome, and Foville's syndrome E.g., gliomas, metastases many of the pontine gliomas start in the region of the sixth and seventh nerve nuclei Progression of the disease is marked by symptoms of...
Neurological manifestations
Secondary to anticoagulation therapy Loss of all sensory modalities below the level of the lesion, e.g. pain, temperature, light touch, position sense, and vibration. Localized vertebral pain accentuated by vertebral palpation or percussion may occur with destructive lesions e.g. infections and tumors , and may have some value for locating the lesion. Pain that is worse when recumbent and better when sitting or standing is common with spinal malignancies - Paraplegia or Initially flaccid and...
Empty sella
E.g., chromophobe, eosinophilic the basophilic form virtually never expands Raised intracranial pressure, chronic E.g., obstructive hydro-cephalus, dilated third ventricle, neoplasm, craniosynostosis E.g., Rathke's cleft cyst, mucocele, arachnoid cyst E.g., aneurysm or ectasia of the cavernous or suprasellar segment of the ICA and caroticocavernous fistula E.g., abscesses, sarcoidosis, histiocytosis, lymphoid adenohypophysitis Due to a deficiency in the diaphragma sella and associated...
Agenesis of the Corpus Callosum
Agenesis of the corpus callosum is one of the more common congenital abnormalities, occurring in 0.7 of births and presenting clinically with intractable seizures and mental retardation. Various degrees of corpus callosum agenesis can occur e.g., complete agenesis, loss of splenium . Associated midline abnormalities include the following. Aicardi's syndrome Agenesis of the corpus callosum, epilepsy, and choroidal abnormalities
Vertical Gaze Palsy
Infarction or hemorrhage of the dorsal midbrain Neurovisceral lipid storage diseases Congenital vertical oculomotor apraxia - Progressive supranuclear palsy - Congenital upward gaze limitation
Syndrome of Inappropriate Secretion of Antidiuretic Hormone and Diabetes
The syndrome of inappropriate secretion of antidiuretic hormone SIADH involves the release of antidiuretic hormone ADH at levels inappropriate for a low serum osmolality. Due to continued water ingestion, the elevated ADH results in water retention, hyponatremia, and hypo-osmolality. SIADH results from partial damage to the supraoptic and paraventricular nuclei or neighboring areas, or from production of ADH by tumor or inflammatory tissue outside the hypothalamus. The laboratory criteria for...
Herniated Disk
Cervical or lumbar disk herniation, and rarely thoracic disk herniation, produces local and radicular pain, occasionally associated with derma-tomal sensory and motor loss. Characteristically, the pain of a herniated disk is worse when the patient is sitting or walking, but relief is usually obtained when the patient lies down. Conversely, spinal cord epidural tumor is usually worse in the recumbent position than when sitting or standing. Magnetic resonance imaging with enhancement should...
Abscess
Pyogenic brain abscess Common organisms causing pyogenic cerebral abscess Aerobic bacteria Staphylococcus aureus, Streptococcus, Gram-negative organisms Escherichia coli, Klebsiella, Proteus, Pseudomonas, Haemophilus influenzae Anaerobic bacteria Streptococcus, Bacteroides, Pepto-streptococcus Tsementzis, Differential Diagnosis in Neurology and Neurosurgery 2000 Thieme All rights reserved. Usage subject to terms and conditions of license. 1. Oligodendroglioma. Axial T2WI shows a space-occupying...
Pseudopapilledema
Congenital disk eleva- A false impression of papilledema, usually caused by tion hyaline bodies drusen within the nerve head. Found in 4 of adults children below the age of 10 years do not have optic nerve head drusen Small full disk Slightly indistinct disk margins, late-branching central vessels, and no central cup a true normal variant True papilledema Almost always bilateral Increased intracranial pressure - Acute obstructive hydrocephalus Perineuritis, neuritis, Syphilitic sarcoid viral...
Calcifications of the Basal Ganglia
Basal ganglia calcifications are seen in 0.6 of CT scans. They usually affect the globus pallidus, and are bilateral and symmetrical, but can be unilateral. These lesions are mainly idiopathic and are often associated with dentate nuclei calcification. Idiopathic These account for over 50 of cases, and can be fa Disorders of calcium Hyperparathyroidism, hypoparathyroidism, and Also known as familial cerebrovascular ferrocalcinosis and characterized by microcephaly, spasticity, epilepsy,...
Causes of Horners Syndrome
Horner's syndrome is an interruption of the sympathetic supply to the eye, resulting in the classic triad of ptosis, miosis, and anhydrosis. - Amyotrophic lateral sclerosis or Lou Gehrig disease Hypothalamus to upper thoracic cord E.g., hemispherectomy massive infarction may cause The sympathetic and spinothalamic pathways in the brain stem lie throughout their course next to each other. Horner's syndrome here is therefore frequently associated with contralateral pain and temperature loss E.g.,...
Intraventricular
Choroid plexus cysts, xanthogranulomas Favored sites Anaplastic, glioblastoma Foramen of Monro Septum pellucidum, lateral ventricle Atrium of lateral ventricle All sites Ependyma of lateral ventricle All sites Cysts Glioependymal, choroid, or inflammatory - Astrocytoma Or other neoplasm arising from the hypothalamus, Nonneoplastic masses Inflammatory cysts, vascular malformations, cysticer-cosis 1. Germinoma. Sagittal T1 WI with a large, solid space-occupying lesion originating from the pineal...
Normal Pressure Hydrocephalus Versus Brain Atrophy
Although brain atrophy and normal pressure hydrocephalus NPH often share the finding of dilation of the ventricular system, the prognostic and therapeutic implications of the two entities are markedly different. Atrophy reflects the loss of brain tissue, whether it is cortical cell bodies, axonal subcortical degeneration, or demyelination. Generally, there is no treatment for atrophy, whereas hydrocephalus can often be treated with ventricular or subarachnoid space shunts and or removal of the...
Fig 1 Suprasellar lesions neoplastic
I, 2. Pituitary macroadenoma. Coronal T1 WI with a pituitary macroadenoma in close relationship with the optic chiasm presenting a heterogeneous, post-contrast high intensity signal. 3. Pituitary macroadenoma. Sagittal T1 WI shows a pituitary tumor with a heterogeneous postcontrast high intensity signal with cystic and or necrotic features in its posterior section filling the suprasellar cisterns and exerting compression on the optic chiasm. 4, 5. Craniopharyngioma. A suprasellar...
Brain Stem Vascular Syndromes
Ipsilateral CN III palsy, including Ipsilateral CN III palsy, usually Ipsilateral CN III palsy, usually CN III n. nucleus Edinger-Westphal CN III n. nucleus Edinger-Westphal mesencephalic reticular formation red nucleus CN III Fig. 15 Brain stem vascular syndromes a Midbrain superior colliculus Weber syndromes a corticospinal and corticopontine tracts contralateral hemiplegia including the face b parasympathetic root fibres of CN III ipsilateral oculomotor nerve paresis with fixed and dilated...
Acute Monoplegia
A child's failure to use a limb indicates that there is pain, weakness, or both in the limb. Pain is usually caused by injury, infection, or tumor. Complicated migraine may cause weakness. Pain and weakness together are signs of plexopathy, syringomyelia, and tumors of the cervical cord or brachial plexus. The leading causes of monoplegia are plexopathies and mononeuropathies. A demyelinating disorder of the brachial and lumbar plexuses Ischemic nerve damage due to vasculitis Postasthmatic...
The differential diagnosis of Lhermittes signs includes
Spinal metastasis Cervical spondylosis Cervical disk herniation Multiple sclerosis Posttraumatic syndrome Subacute combined degeneration Cisplatin chemotherapy Cervical radiation Patients may also present with progressive weakness, sometimes with lower motor neuron signs including fasciculations, in association with sensory loss and autonomic dysfunction such as incontinence and postural hypotension. - CSF analysis typically shows inflammatory changes - MRI usually shows a normal spinal cord on...
Cerebellopontine Angle 1
Acoustic schwannoma Most common mass, up to 75 of cases Meningioma Second most common lesion, up to 10 of cases Also known as congenital cholesteatoma or pearly tumor 5-7 Also known as glomus jugulare tumor a chemodec-toma arising from the jugular foramen and extending into the CPA 2-10 2 - 5 . The trigeminal and facial nerves are probably the most common sites of nonacoustic schwannomas. Other cranial nerves involved are VI, IX, X, XI, and rarely XII 1 primary in the CPA or extension via the...
Cavernous sinus and orbital processes
Iatrogenic postsurgical complication E.g., clivus tumor or nasopharyngeal tumor invading the intracranial cavity Posterior fossa and cerebellopontine angle explorations E.g., meningioma, pituitary adenoma with apoplexy, and metastases such as nasopharyngeal tumor spreading into the intracranial cavity or maxillary antral carcinoma invading the floor of the orbit, and multiple myeloma Orbital trauma with entrapment of connective tissue and muscles Pseudotumor Tolosa-Hunt syndrome Thyroid...
Thoracic Pain
Metastatic tumors are more common 66 than primary spinal tumors 30 the remaining 4 are prevertebral tumors invading the spinal canal. The frequency of skeletal metastases is much higher for some tumors 84 for prostatic cancer and 74 of breast cancer Benign tumors and tumor-like conditions e.g., exostosis, osteoid osteoma, fibrous dysplasia, aneurysmal bone cyst, hemangioma, etc. Represent approximately 25 of primary spinal tumors 90 of spinal meningiomas are purely intradural, and the remaining...
Foramen Magnum
In 25 of Chiari I patients secondary syrinxes due to trauma can be seen Acute transverse myelopathy Miscellaneous e.g., radiation, AIDS, vascular AVM Commonly of low grade, 50 occurring in the cervicomedullary junction. Extension of spinal cord gliomas into this area is also common. Other types of gliomas, however, such as anaplastic astrocytoma, gangliogan-glioma, ependymoma are also found here Inferior extensions of medulloblastomas in children and hemangioblastomas in adults are common in...
Spinal Extradural Cysts
Spontaneous spinal nerve root diverticula and cysts Tarlov cysts Posttraumatic or postoperative meningeal diverticula Spinal ganglion cysts and spinal synovial cysts These cysts arise as an evagination or herniation of the arachnoid that gradually enlarges. Its neck eventually closes, creating a cyst that no longer communicates with the CSF space. The cysts are located exclusively or primarily in the thoracic spine in 86 of cases, and less frequently in the cervical region 2.5 and lumbosacral...
Multiple Lumbar Spine Surgery Failed Back Syndromes
A history of failed lumbar spine surgery represents a diagnostic and therapeutic challenge for the physician. The first step is to distinguish between patients whose back or leg pain originates from a systemic cause e.g., pancreatitis, diabetes, abdominal aneurysm and those with a mechanical problem a thorough medical evaluation should therefore be undertaken in this group at the same time as the neurosurgical evaluation is carried out. Patients with profound emotional disturbances and...
Spinal Intradural Cysts
Intraspinal neurenteric cysts form a spectrum that merges with intraspinal teratomas and intraspinal dermoids and epidermoids. More than 60 of the cases are diagnosed in the first 20 years of life 44 are located totally or partially in the cervical spinal canal, 37 are located in the thoracic spinal canal, and 19 in the lumbosacral spinal canal. The neurological signs and symptoms of a slowly progressing mass are associated by congenital anomalies, such as thickened or pigmented skin, a...
Sources of subarachnoid metastases
- Primary neuroec-todermal tumors PNETs - Glioblastoma multiforme, anaplastic astrocytoma - Chronic meningitis Fungal and granulomatous meningitis. Chronic menin- gitides have a predilection to invade the basal cisterns Coccidioidomycosis imitans meningitis Cryptococcus neoformans meningitis Posttraumatic basal cranial adhesions
Multifocal White Matter Lesions
Hypertension and ischemic white matter lesions leukokraurosis Increases with age, and has also been seen with chronic hypertension. There are two types of ischemic white matter lesions - Lesions involving the watershed distribution of the major brain arteries - Lesions caused by intrinsic disease of the small penetrating medullary arteries arteriolar sclerosis Enlargement of these perivascular spaces with age and hypertension, associated with thinning, pallor and atrophy of the adjacent myelin,...
Corpus Callosum Lesions
Near the top of the list of lesions involving the corpus callosum are There is a propensity for shearing injuries in this location, because of its relatively fixed location spanning the interhemispheric fissure White matter lesions - Multiple sclerosis Severe hydrocephalus, and after ventricular shunting The frequent localization of acute and chronic MS lesions in the corpus callosum is thought to be due to tracking of these lesions along the ependymal veins from the ventricular surface into...
Clinical Differentiation of Cauda Equina and Conus Medullaris Syndromes
Clinical symptom Conus medullaris Cauda equina Bilateral, symmetrical Perineum and thighs Saddle distribution Bilateral, symmetrical Sensory dissociation present presents early Symmetrical, mild, asymmetrical Atrophy absent Achilles reflex absent Patellar reflex normal Early, severe Absent anal and bulbo-cavernosus reflex Sensory dissociation absent presents relatively late Reflex abnormalities less common Adapted from DeJong RN. The neurologic examination incorporating the fundamentals of...
Skull Base
Extracranial lesions - Nasal, paranasal sinus malignant tumors Orbital plates, frontal bones, cribriform plate, planum sphenoidale Occur in up to 30 of anterior skull base cases. Carcinomas represent 98 of adult nasopharyngeal tumors Squamous cell carcinomas 80 , adenocarcinomas 18 Rhabdomyosarcoma the most common soft tissue sarcoma in children up to 35 of these lesions occur here Esthesioneuroblastoma, or olfactory neuroblastoma arises from the bipolar sensory cells and is histologically...
Transient Monocular Blindness
Great vessel or distal internal carotid atheroembolism Drug abuse-related intravascular emboli 3-5 minutes in duration quadrantic, altitudinal, or total visual loss, corresponding in distribution of retinal arterioles associated with contralateral hemiplegia with or without hemihypoesthesia. The most common type of embolus is cholesterol embolus, manifesting as a glistening, shiny, slightly irregular object with the narrowed retinal vessel, corresponding to a field defect, and in other retinal...
Internuclear Ophthalmoplegia
This is a disorder of horizontal eye movements due to a lesion of the medial longitudinal fasciculus MLF in the mid-pons, between the third and sixth cranial nerves. The MLF lesion produces disconjugate eye movements and diplopia on lateral gaze, since impulses to the lateral rectus travel abnormally, whereas those to the medial rectus are intact. Intrinsic and extra-axial brain stem and fourth ventricular tumors Chiari types II and III malformation and associated syringobulbia Most common in...
Postoperative Brain Scar Versus Residual Brain Tumor
There is nothing more frustrating for the neurosurgeon than a postoperative CT scan or MRI showing residual tumor after a supposedly complete resection. Granulation tissue, which enhances on CT and MRI due to its fi-brovascular nature, develops 72 hours after surgery. After that time, it is consequently difficult to distinguish between enhancing surgical bed tissue and marginal residual tumor, assuming that there was preopera-tive tumor enhancement. The scan enhancement may persist for several...
Craniosynostosis
Trigonocephaly Frontal plagiocephaly Elongated skull from front to back, with the biparietal diameter the narrowest part of the skull e.g., boat or keel-shaped head due to premature closure of the sagittal suture Triangular head angular and pointed forehead with a prominent midline bony ridge, due to premature closure of the metopic suture Ipsilateral flattened frontal region with contralateral outward bulging and marked facial asymmetry har-lequin eye due to unilateral coronal suture synosto-...
Atlantoaxial instability
Traumatic lesions in the craniovertebral junction E.g., Paget's disease, osteomalacia, rheumatoid cranial setting E.g., achondroplasia, occipital dysplasia, rickets The high incidence of craniovertebral anomalies and increased incidence of general ligament laxity may lead to instability in 30-40 of such patients. The usual onset of neurological symptoms is between seven and 12 years The cervical spine is variably affected in 44-88 of patients, with conditions ranging from minor asymptomatic...
Macrocephaly or Macrocrania
Macrocephaly refers to large cranial vault. - Thalassemia or anemias with increased marrow activity Megalencephaly Familial macrocephaly Aqueduct stenosis, stenosis of the foramen of Monro causing asymmetrical enlargement, Dandy-Walker cyst, Chiari malformation - Meningeal fibrosis postinflammatory, posthemorrhagic, posttraumatic - Malformation, destructive lesions hydranen-cephaly, holoprosencephaly, porencephaly E.g., hypoparathyroidism, galactosemia
Posterior Fossa Tumors
Differentiation between medulloblastoma, ependymoma, and astrocytoma based on their radiological characteristics Fig. 3 . Hypodense nodule enhances cyst does not 4 th ventricle, superior medullary velum 1. Medulloblastoma. Axial MRI T1 WI shows a solid space-occuping lesion with a moderate signal intensity on T2WI which occupies the area behind the 4th ventricle exerting pressure on it. 2. Ependymoma. Axial MRI T1 WI shows a multilobular space-occuping lesion with solid features, which are...
Microcephaly or Microcrania
Perinatal damage E.g., cortical atrophy from hypoxia or ischemia - Hereditary nonchro-mosomal syndromes Intrauterine injury or fection TORCH E.g., achondroplasia, achondrogenesis, thanatophoric dwarfism and metaphoric dwarfism, cleidocranial dysplasia, Sotos syndrome E.g., Hurler, Hunter, Morquio, gangliosidosis GM E.g., neurofibromatosis, tuberous sclerosis E.g., Fanconi syndrome, Prader-Willi syndrome, Seckel syndrome, Rubinstein-Taybi syndrome E.g., toxoplasmosis, rubella, cytomegalic...
Meningeal Enhancement
In 80 of patients indicating inflammatory or chemical arachnoiditis from blood Bacterial, viral, syphilitic, and granulomatous Postcraniotomy meningeal enhancement Extraskeletal mesenchy-mal osteocartilaginous tumors Miscellaneous and rare causes of dural enhancement CSF leaks, CSF shunting and intracranial hypotension Histiocytosis Sarcoidosis Rheumatoid disease Idiopathic pachymeningitis Mucopolysaccharidoses e.g., Gaucher disease Glioblastoma multiforme Wegener's granulomatosis Glioneuronal...