EM neurology Flashcards
True synostosis of the lambdoidal suture is rare, whereas positional deformity causing occipital flattening is becoming more and more common since the Back to Sleep campaign in 1994 began recommending infants be placed in a supine position when sleeping as a deterrent to SIDS.
When viewed from the back, a tilt in the base of the skull is a distinctive feature found with true lambdoidal craniosynostosis.
Spinal cord tethering may cause progressive neurologic deficits, including decreased muscle strength or increased tone, deteriorating gait, change in sensory level, urologic dysfunction or orthopedic deformities such as hip dislocation, pes cavus or scoliosis.
Although anatomical evidence of some degree of tethering is evident in almost all myelomeningocele patients, surgical untethering is reserved only for those having progressive signs and symptoms. Diagnosis is thus based on clinical grounds and not imaging studies.
The most appropriate step in the management of this infant is to administer injection magnesium sulphate because hypocalcemia in an infant of diabetic mother (IDM) may not respond to calcium therapy until hypomagnesemia is treated.
However it is better to estimate serum magnesium levels before giving magnesium sulphate. About 25-50% of IDMs have hypocalcemia during the first 24-48 hours.
Lennox-Gastaut epilepsy syndrome is characterized by the clinical triad of diffuse slow spikes and waves on EEG, mental retardation, as well as multiple types of generalized seizures, especially atypical absences and tonic and atonic seizures. Age of onset is between 2 and 8 years. It is further classified as symptomatic or cryptogenic.
33% of the symptomatic patients have had infantile spasms. Prognosis is poor for neurocognitive outcome and seizure control. Intellectual quotient deteriorates with age and tonic seizures persist, though the slow spike wave EEG pattern tends to resolve.
Topiramate is one of the newer antiepileptic drugs used to treat complex partial seizures (CPS). Its primary adverse effects include
cognitive impairment, weight loss, and kidney stones.
Synostosis of the _____ sutures causes trigonocephaly, resulting in a keel-shape deformity of the central forehead. Trigonocephaly is usually mild and requires no treatment.
metopic
Infantile spasms typically have an onset between the ages of 4 to 9 months, and occur in clusters associated with a typical EEG pattern. This pattern, known as hypsarrhythmia, is characterized
by high voltage, chaotic slowing, multifocal spikes, and marked asynchrony. A patient will exhibit flexor, extensor, and mixed flexor/extensor fits.
Simple febrile seizures occur in 2 - 5% of children less than 5 years of age. Criteria of simple febrile seizure include:
Child is between 6 months and 5 years of age
Child is febrile
The seizure is generalized (nonfocal)
Seizure duration is < 15 minutes
There is no flurry of recurrent seizure activity
Child has a normal neurologic exam
There is no history of neurological or central nervous system abnormalities.
Friedreich’s ataxia is a hereditary degenerative disorder which becomes apparent between 2 and 16 years. It is characterized by
kyphosis, absence of tendon reflexes indicating degeneration of spinal cord, and dysarthria, that is almost universally present. It has an autosomal recessive inheritance. The progression is rapid, but shows no sign of ophthalmoplegia or dementia. Nystagmus is a frequent part of the clinical picture. Nystagmus is an oscillating eye movement, with slow movement in one direction, and subsequent saccadic jerk back to the midline of gaze. The direction of nystagmus refers to the fast component. On the other hand, optokinetic nystagmus is normal adaptation to fixate on some objects.
The risk that the patient will experience another febrile seizure in the future is dependent on the age at the time of the initial simple febrile seizure.
The recurrence rate is 50% in children under 1 year of age and 30 - 35% in children over 1 year of age. The risk of developing epilepsy is approximately twice that of the general population (2% vs. 1%) if the child has no underlying neurological abnormalities and did not have a complex febrile seizure.
Typical childhood absence seizures can be triggered by
hyperventilation in 80% of children as well as by photic stimulation in those with absence epilepsy. It begins between 3 and 10 years of age in otherwise normal children and seizures are characterized by brief, 5-20 second lapses in consciousness, speech, or motor activity, sometimes associated with flickering of the eyelids.
Absence seizures are never accompanied by an aura or postictal drowsiness, but lip smacking or eye blinking automatisms may be observed during the seizure. Numerous seizures can occur every day. The EEG shows classic
ictal generalized 3-Hz spike and wave discharges. Good response is seen with use of valproic acid, ethosuximide, or lamotrigine. Seizures usually remit by adolescence or early adulthood.
Diffuse slow spikes and waves on EEG, mental retardation, and multiple types of generalized seizures are characteristic of
Lennox-Gastaut syndrome. It typically manifests at 2- 8 years of age and has a poor prognosis for neurocognitive outcome and seizure control.
Acute cerebellar ataxia affects children between 1 and 6 years of age. It shows sudden onset and rapid progression until spontaneous recovery in 1 to 6 months, with rare residual effects. The disease manifest 3-14 days following the onset of a viral illness. Patients are frequently irritable, vomit, and have resistance to neck flexion. Cerebellar dysfunction can have a variety of manifestations:
dysmetria (inability to gauge speed), dysdiadochokinesia (inability to perform alternating movements), dysarthria (slurred speech), hypotonia (lack of resistance to passive movements), nystagmus (involuntary eye oscillation), and titubation (head bobbing and unsteady posture when sitting).
the infant presents with a loss of motor and language milestones beginning at about 5-6 months of age. She has hypotonia and moderate hepatosplenomegaly. She also has apathy, and both visual and hearing loss. Fundus examination shows a cherry red spot in the macular region. Sandhoff disease is fatal, with most children dying by the age of 3.
Sandhoff disease is a severe form of Tay Sach’s disease. They can both be distinguished by individual estimations of beta-hexosaminidase A and beta-hexosaminidase B. Moderate to severe hepatosplenomegaly is present in Sandhoff disease but it is absent in Tay-Sach’s disease.
Hexosaminidase A has 2 subunits: 1 alpha and 1 beta. Hexosaminidase B has 2 beta subunits. Mutation of the alpha subunit(s) manifests as Tay Sach’s disease, while mutation of the beta subunit(s) causes Sandhoff disease.
