Lecture 42 March 23rd-nervous

1DDX: LECTURE 42 – MARCH 23rd, 2007 CONDITIONS OF THE NERVOUS SYSTEM Page 1 CEREBRAL PALSY • “Palsy”: damaged, something is wrong with it. It is an old word. • Applied to a group of congenital nervous system disorders. • Christy Brown in “My Left Foot” (1989) had CP

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Main indications in baby is movement. Kids usually have “cat” response: will move body to protect selves in case they fall. CP kids don’t have this response. This is a brain response, not spinal cord. Pathology is in BRAIN, not in spinal cord Spastic paralysis: they have nerves going to all systems, but they have an inability to response. Could be bulbar/cerebellar/cerebral centre that is responsible. Spastic: usually cerebral pathology. Flaccid: usually peripheral pathology They have speech impairments: can make sounds, but hard to understand without spending time with them. Intellectual deficits.

Etiology In notes, in order of most likely to least likely. Brain injury: not likely because we see this in all types of delivery.

Picture above: examples of movements that you might see in CP. Teach them the way that you would teach any other child: may just take them a little longer. On autopsy, the source of the pathology is not visible in the brain. STROKE • Can be caused by atherosclerotic plaque, air embolus, injected substance… • Air: would need 60-100 mL of air to block an artery. Less than this: it would just dissolve in blood. • Blood exchanges nutrients/oxygen with brain tissue via CSF. • Rapidly evolving symptoms, can be focal or global.

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DDX ischemia: symptoms won’t last >24 hours; stroke is permanent, TIA is reversible. You do recover some function in stroke… Stroke: in brain, always looks triangular due to pattern of blood flow (“flowers”). Area that is not perfused will die. Lacunes: can form from chronic hypertension. A unique type of infarct that is associated with hypertension. These happen in the pons: which is a commissure. Connections between different parts of the brain. Associated with cranial nerves: get focal movement problems. Spastic paralysis in one area… Usually the other side of the brain can compensate for some amount of damage. CTs are generally “messy” in early strokes, MRIs easier to read. Looking for areas of varying density, liquification, on CT. DDX LECTURE 42, MARCH 23rd, 2007 – PAGE 1

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There is redundancy built in to our brains so that we can recover from events like strokes: parallel area on the other side takes its place. Your brain has to learn how to communicate using the other side. Hard-wired to take over control of this area if needed. The brain also has plasticity, where another area of the brain, usually on the same side as the damage, learns to take over the function of the damaged area.

HYPERTENSION • Under CNS control • If you get excited, the cerebral arteries “alter their calibre” to maintain perfusion. • Brain will sometimes raise blood pressure to make sure that it can get oxygen. • Hypo/hypertension: beyond the auto-regulatory range. Body can’t compensate for changes in blood pressure. • “opathy” implies pathology VENOUS INFARCTION • Sinuses carry blood through the brain. All connected. • Superior sagittal sinus: can be subject to thrombosis. Can happen after childbirth (in the mother) • See seizures and headache • Cavernous sinus: lots of nerves and arteries go through it. When it swells from thromobosis, will affect artery, nerve, vein. Swollen eyelid, edematous conjunctiva, all nerves going to eye will be affected: abducens, oculo-motor, CNII (doesn’t pass through it, but pressure is exerted on it.) • History will give you a clue as to what has happened. TRANSIENT ISCHEMIC ATTACK • An area is not being perfused for a period of time. • Presence of symptoms will always be determined by where the lesion is. Symptoms will tell you where the attack is. Location isn’t that relevant though because it is transient. Have to get to the root of the problem and solve it. • Look at symptoms to determine where it happened (see chart). • Vertebrobasilar is lower down: see different symptoms. CONCUSSION • Can’t really do much at first: watch and wait. • May or may not lose consciousness. • Body’s response to trauma: you pass out so that you will stop doing the activity that caused the trauma. • May be residual damage after successive concussions: contusions. • If you see other symptoms, you have gone beyond the point of a simple concussion. Organic changes like motor or personality changes, this falls under a different definition. CONTUSION (BRUISE) • Looks like a bruise anywhere else on the body (post-mortem) • Coup and counter-coup lesions: brain moved in skull and caused injury on the other side. • Classified based on where they are. o Epidural hematoma: Usually happens to middle meningeal artery. Break bone under it and you will definitely have a bleed. Pressure is the problem: buildup of blood squeezes the brain. Amount of CSF produced is reduced. Progressive accumulation of blood. o Subdural: From repeated trauma, ruptured bridging veins. On CT scan (in class): bleed is dispersing around the brain. Has somewhere to go under dura.

DDX LECTURE 42, MARCH 23rd, 2007 – PAGE 2