Exam IV- BrainStem Flashcards
What is the name for the more ventral portion of the brainstem?
The basilar region
What is the more posterior/dorsal region of the brainstem?
The tegmentum
What is posterior to the cerebral aqueduct in the midbrain?
The tectum
Where is the reticular formation in the brainstem?
The tegmentum area (dorsal portion of midbrain, pons, & medulla)
Where will I find Ascending pathways in the brainstem?
The tegmentum, makes sense because sensory is always dorsal
Where will I find Descending pathways in the brainstem?
The basilar region, makes sense because motor is always ventral
Where do the spinalThalamic ascending pathways cross?
The spinal cord, by the time we get to the brainstem they are crossed.
Where does the DC-ML ascending pathway cross?
The medulla
What does DC-ML stand for? What is its function?
Dorsal Column-Medial Lemniscal, fine touch and conscious proproception from the body
What is the function of the Trigeminal Lemniscal pathway?
Fine touch and conscious proprioception from the face
What is the function of the SpinoThalamic Pathway?
Pain and temperature from the body
What is the function of the Trigeminal Thalamic pathway?
Pain and temperature from the face
For the ascending pathways, what is the result of a lesion BELOW the decussation?
An IPSIlateral deficit
For the ascending pathways, what is the result of a lesion ABOVE the decussation?
CONTRAlateral deficit
For the ascending pathways what is the result of a lesion AT the decussation?
BIlateral deficit
What is the main function of the rostral portion of the Reticular Formation? What is the fancy science name of this portion?
Alertness, like the alarm clock!…PontoMesencaphalic
What is the main function of the caudal portion of the Reticular Formation? Whats the fancy scientific name for this portion?
Vital Functions….PontoMedullary
What is the name of the system that regulates alertness, sleep/wake, consciousness in the rostral reticular formation?
(ARAS) Ascending Reticular Activating System
What is a classic result of a lesion to the Rostral Reticular Formation?
A coma
What are the 5 N.T.s associated with the Rostral Reticular Formation? What is a main fxn of each?
- Ach(alertness,memory) 2.NorEpi(alertness,mood) 3.Dopamine(movement,initiative,memory) 4.Seratonin(mood) 5. Histamine(alertness)
What are the four main inputs to the Rostral Reticular Formation? Think of reasons you can’t sleep :)
1.Fronto-Parietal Assoc. Cortices (Thinking too much in bed)2. Limbic&Cingulate Cortices 3.Thalamus 4. SpinoReticular Tract(part of Spinothalamic System CANT SLEEP W PAIN/Temperature)
What are the 6 main functions of the Caudal Reticular formation?
- Respiration 2. Heart Rate 3. Blood Pressure Regulation 4. Descending Motor Control 5. C.N. Reflexes 6. LOTS of Involuntary movements (coughing, hiccups…)
What are the 6 brainstem lesions we discussed?
1.INFERIOR Alternating Hemi-Ple-Gia 2.Wallenberg’s Syndrome 3.Acoustic Neuroma 4. MIDDLE Alternating Hemi-Ple-Gia 5. Trigeminal Alternating Hemi-Ple-Gia 6. SUPERIOR Alternating Hemi-Pel-Gia (Weber’s)
Where is the source of Inferior Alternating Hemiplegia? What blood supply problem?
Source: AnterioMedial Medulla Blood: Anterior Spinal Artery
What are the three main structures affected with Inferior Alternating Hemiplegia?
- Hypoglossal Nuc/Nerve 2. Pyramid 3. Medial Lemniscus
What are 2 symptoms of Inferior Alternating Hemiplegia?
- IpsiLateral paralysis of tongue (towards side of lesion) 2.UMN=ContraLat sensory/motor loss (ABOVE DECUSS=CONTRA)
Where is the source of Wallenberg’s Syndrome? What artery is the problem?
Where: Lateral Lesion of medulla Blood: PICA
What are 3 main symptoms of Wallenberg’s syndrome?
- Loss of pain and temperature 2. Difficulty swallowing 3. DIZZINESS!! main one!!!
Where is the source of an Acoustic Neuroma (Schwannoma)?
The cerebellaponitne angle (remember the picture!?). NO blood problem because its a tumor
What are the CNs involved with Acoustic Neuroma? Since you know the CNs what are the symptoms?
7: Bell’s, HyperAccusis 8:Tinnitus, Nystagmus and if its big enough 5. Alternating Hemianesthesia
Where is the source of a Middle (Abducens) Alternating HemiPlegia? What is the blood supply problem?
The Caudal Pons, branches of the Basilar Artery
What are the 4 structures affected in the Middle(Abducens) Alternating HemiPelgia?
- VI (ABDUCENS) 2. VII 3.CorticoSpinal Tract 4. Medial Lemniscus
What are the 4 main symptoms of MiddleA.H.? Think structures affected!
- IPSIlat adduction of eye (c/o VI being out) 2. Positive Babinski sign (c/o Cort.Spin.Tract) 3. Bell’s (VII) 4. CONTRA lat sensory loss (ML )
Where is the problem with a Trigeminal Alternating Hemiplegia? Blood Supply?
Where: the Mid Pons BLOOD: Basilar Art
How many structures are affected my Trigemninal AH? What are the 3 MAIN structures and what are some symptoms?
There are 7 freaking structures affected…..#1) V: Ipsilat BITE DOWN, SENSATION (all freaking over) #2)Ascending and #3)Descending Tracts: Body sensation and Motor
Where is the problem with Weber’s Syndrome? (SUP A.H.) Blood Supply?
Where: The Midbrain BLOOD: Basilar Art., Post Cerebral Art
What are the 3 structures involved in Superior AH/Weber’s? What are the LMN lesion signs? What are the UMN lesion signs?
III, CorticoSpinal, CorticoBulbar….LMN: Ptosis, Pupil Dilation, External Strabismus, Inability to move the eye in any of the III motor directions……UMN: pos babinski, CONTRAlat paralysis CONTRA lower face
Which part of the face receives BILATERAL input from UMNs?
The UPPER part of the face
Which part of the face receives CONTRALATERAL input from UMNs?
The LOWER part of the face
