neurological

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Here’s a clearer version of my ADHD info graphic
Happy ADHD awareness month everyone!!

A Collection Of Books By Neurologist Oliver Sacks

If you’re interested in neuroscience or psychology, I’d highly reccomend any book by Oliver Sacks! I get asked a lot about books to read so you can also check out this video I made with my top 7 and this masterpost which includes websites where you can learn more!

1. Migrane

For centuries, physicians have been fascinated by the many manifestations of migraine, and especially by the visual hallucinations or auras- similar in some ways to those induced by hallucinogenic drugs or deliria–which often precede a migraine. Dr. Sacks describes these hallucinatory constants, and what they reveal about the working of the brain. 

2. Awakenings

Awakenings is the remarkable account of a group of patients who contracted sleeping-sickness during the great epidemic just after World War I. Frozen in a decades-long sleep, these men and women were given up as hopeless until 1969, when Dr. Sacks gave them the then-new drug L-DOPA, which had an astonishing, explosive, “awakening” effect. Dr. Sacks recounts the moving case histories of these individuals, the stories of their lives, and the extraordinary transformations they underwent with treatment.

3. The Island of The Color Blind

Oliver Sacks has always been fascinated by islands, and this book is an account of his work with an isolated community of islanders born totally colorblind.  He listens to these achromatopic islanders describe their colorless world in rich terms of pattern and tone, luminance and shadow.

4. Uncle Tungsten

A book about Sacks’ childood;  his discovery of biology, his departure from his childhood love of chemistry and, at age 14, a new understanding that he would become a doctor.

5. An Anthropologist on Mars

This book talks about 7 seemingly paradoxical neurological conditions: including a surgeon consumed by the compulsive tics of Tourette’s Syndrome except when he is operating; an artist who loses all sense of color in a car accident, but finds a new sensibility and creative power in black and white; and an autistic professor who has great difficulty deciphering the simplest social exchange between humans, but has built a career out of her intuitive understanding of animal behavior. 

6.  Seeing Voices

 A journey into the world of deaf culture, and the neurological and social underpinnings of the remarkable visual language of the congenitally deaf. Sacks writes “The existence of a visual language, Sign, and the visual intelligence that goes with its acquisition, shows us that the brain is rich in potentials we would scarcely have guessed of, shows us the almost unlimited resource of the human organism when it is faced with the new and must adapt.”

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Phineas Gage is one of the most famous patients in the history of neuroscience. He was 25 years old when he experienced a serious accident at his work place, where a tamping iron was shot through his head - entering under his eye socket at exiting through the top of his head - after an explosive charge went off. The tamping iron was over a metre long, and after exiting Gage’s head landed 25m away. 

Initially Gage collapsed and went into minor convlusions, but recovered quickly and was able to speak after a few minutes. He walked with little assistance to an ox-cart and was brought to a nearby physician. Initially the physician did not believe his story because he was in such good condition, but was convinced when: 

Mr. G. got up and vomited; the effort of vomiting pressed out about half a teacupful of the brain, which fell upon the floor.

Gage exhibited a number of dramatic behavioural changes following the accident. Harlow, the physician who initially treated Gage, described this change “He is fitful, irreverent, indulging at times in the grossest profanity (which was not pre­vi­ous­ly his custom), manifesting but little deference for his fellows, impatient of restraint or advice when it conflicts with his desires”. However the surgeon Henry Jacob Bigelow described his condition as improving over the course of recovery, stated he was “quite recovered in faculties of body and mind”. This may have been early evidence of neural plasticity. This recovery was also reported by a physician who knew Gage while he lived in Chile, who described his ability to hold on a full time job as a Concord coach driver, a job that required exceptional social skills.

Gage’s neurological deficits following his traumatic brain injury is thought to have been exaggerated and distorted over the course of history, to the point that he is often portrayed as a ‘psychopath’. Scientific analysis of the historical accounts of Gage’s life following his accident, namely by the psychologist Malcolm Macmillan, find that these distorted accounts are most likely untrue, and that Gage made a very good recovery.

Post-mortem analysis of the Gage case concluded that it was the left frontal lobe that was damaged in the accident, although further neurological damage may have resulted from infection. Combined examination of the Phineas Gage case with the other famous cases of Tan and H.M. have concluded that social behaviour, memory, and language are dependent on the co-ordination of a number of different brain areas rather than a single region.

Why Medical School Is Important

This week, I learned a lesson about why medical school is so important. For 4 years, we cram everything into our heads, a little about every specialty. In the end, we all just can’t wait to specialize in our own fields and not have to remember the majority of other stuff we memorized. We can always just consult someone else if we need help right? Well… What if you didn’t recognize the underlying problem in the first place?

This week on neurology, we had a 27 year old woman who was admitted overnight for severe headache. They ended up doing a brain MRI, which showed several small diffusion weighted defects in the posterior brain consistent with strokes. We were asked to see her in the morning for evaluation of “strokes”. I was asked to read her chart and go see her. I thought it was a little odd that a healthy 27 year old had strokes, but you never know. I start reading up and see that her systolic blood pressure has been above 160 all night. They were allowing some degree of permissive hypertension for her strokes. Her creatinine was 1.4. They also assumed this was because of her elevated blood pressures. Finally, there was protein in her urine. I keep reading and notice she is 4 days postpartum. I haven’t even seen the patient yet and put the pieces together in my head. Elevated blood pressure, severe headache with visual scotomas, elevated creatinine, protein in the urine, postpartum… Holy shit, this person has preeclampsia with severe features and needs to be started on a magnesium drip immediately!

I want to go into Ob/Gyn, so naturally I was a little excited that I recognized this. I immediately went to my 70 year old attending and told him this. He looked surprised, and I could tell he probably hadn’t thought about this disease in decades since usually they are admitted to ob/gyn and not neurology. He asked me to call the ob/gyn that was on. Within a few hours, she was seen and started on a magnesium drip for preeclampsia with severe features. My attending and I went to radiology and had them re-read the scan. She had PRES not strokes. This woman could have gone home on aspirin, an anti-hypertensive, and a statin with neurology follow-up and had a seizure a day later from full blown eclampsia.

In the end, I learned about how one person going down the rabbit hole of one diagnosis can lead to a series of several providers going down it as well. It was a shining moment for me as a medical student, not going to lie. But it also showed me the importance of being well read and not shutting out my mind to other specialties. We all need to know a little about everything and when to realize our limits and consult someone else. And a lot of the time, medical school is the only immersive experience we will get in many of these specialties. It matters more than just learning for the sake of the shelves.

Photographs of William W. Keen’s successful operation to remove a brain tumor from a 26-year old patient, 1887. The patient was a carriage maker who exhibited symptoms of severe headaches, seizures, and partial blindness; he also had a history of a head injury and was prone to aphasia.

Owing to Keen’s demands at that proper antiseptic measures were taken for the operation (including removing the carpet and cleaning walls and ceiling), the tumor was removed after a two hour operation. Despite some complications with wound closure and cerebrospinal fluid leak, the patient lived for thirty years, even donating his brain to his surgeon for anatomical study.

Journal of the American Medical Association, 1918.

Types of Spinal Cord Injury (SCI)

Typical complications of SCI include:
Autonomic Dysreflexia (AD)
Orthostatic Hypotension (OH)
Spinal Shock
Spasticity and Hypertonia
Contracture
Pain
Deep Vein Thrombosis (DVT)
Heterotopic Ossification
Osteoporosis and Risk of Fracture
Pressure Sores
Impaired Temperature Control
Pulmonary Impairment
Bladder, Bowel and Sexual Impairments

Follow RehabAtHome for more contents in the future! 📚🤗

Day 11 (10/9): Favorite subject

My favorite subject is anatomy, specifically neuroanatomy!  I love learning about all the different components that go into making the body function as we know it.  A follow-up favorite subject is physiology since it is the study of the function of these anatomical components.

Book: Anatomical Atlas (Maud Jepson)

Note: the diagrams are from this book (though I wish I could draw this well!)
Neurotransmitters

Central nervous system

  • Glutamate 
  • GABA 
  • Glycine 
  • Dopamine 
  • Serotonin 
  • Noradrenaline 
  • Histamine 
  • Orexin 
  • Endorphins 

Peripheral nervous system 

  • Noradrenaline 
  • Acetylcholine 

Neurotransmitter synthesis/packaging 

  • Some neurotransmitters are readily available amino acids eg Glutamate, glycine 
  • Some are synthesised by the cells that secrete them eg GABA, noradrenaline, dopamine 

Noradrenaline synthesis:

Packaging

  • In the presynapse, neurotransmitter is contained in vesicles 
  • The neurotransmitter must be packaged into the vesicle ready for release 
  • Uses transporters and proton gradients to package 

[packaging and release - above]

  • Neurotransmitter release is quantal – Each vesicle contains the same amount of neurotransmitter 
  • Therefore it is the number of vesicles fusing which determines the post synaptic potentials 
  • membranes must fuse for release - membrane fusion is energetically unfavourable so must be catalysed by something

SNARE Hypothesis 

  • Proteins on the presynaptic membrane ‘grab’ proteins on the vesicle membrane 
  • These SNARE proteins pull the two membranes close together 
  • SNARE proteins provide most of the energy for membrane fusion
  • v-SNARE (VAMP2) – on vesicle membrane 
  • t-SNAREs (syntaxin1A, SNAP-25) on target membrane 
  • Bind together to make SNARE complex 
  •  SNARE ‘zippering’ forces the membranes close together 
  • Spontaneous, highly energetically favourable 
  • Once assembled, they require ATP hydrolysis to separate them 
  •  Ca2+ binding to synaptotagmin provides extra energy to fuse the membranes

Neurotransmitter release

  • synaptic vesicle release sites are highly organised and regulated
  • exocytose into synaptic cleft

presynaptic active zone:


Neurotransmitter detection

  • Ionotropic (ion channel coupled) – Glutamate, GABA, Glycine 
  • Metabotropic (G-protein coupled) – monoamines, histamine etc. 
  • Some have both kinds, e.g. glutamate, GABA 
  • Ionotropic responses are faster 
  • Metabotropic responses can have more diverse effects 

Glutamate receptors

  • Glutamate is the main excitatory neurotransmitter in the brain 
  • Three classes of ionotropic receptor – AMPA – NMDA – Kainate 
  •  Named after pharmacological agonists 
  • All let in positive ions when they bind glutamate 
  • Glutamate also has a family of metabotropic receptors – mGluRs – These modulate neurotransmission 

AMPA Receptors 

  •  Main fast excitatory receptor 
  • Strength of a synapse is largely determined by its complement of AMPARs
  •  More AMPAR in the post-synaptic membrane = stronger synaptic transmission 

NMDA Receptors 

  • Minor role in postsynaptic firing 
  • Major role is in synaptic plasticity 
  • NMDA receptors are calcium permeable 
  • require strong neurotransmitter release to open 

So I sat the GAMSAT yesterday 💉 And today (after a substantial amount of sleep) I started my day by reading this wonderful novel. 

For those of you who haven’t read it, I’d 100% recommend! For anyone wondering, the flash cards are called Moore’s Clinical Anatomy Flash Cards ☀️☀️

P.S. You can follow my Instagram here: taylamaree7

bbc.com
Experts excited by brain 'wonder-drug' - BBC News
A drug for depression could stop all neurodegenerative diseases, including dementia, scientists hope.

Scientists hope they have found a drug to stop all neurodegenerative brain diseases, including dementia.

In 2013, a UK Medical Research Council team stopped brain cells dying in an animal for the first time, creating headline news around the world.

But the compound used was unsuitable for people, as it caused organ damage.

Now two drugs have been found that should have the same protective effect on the brain and are already safely used in people.

“It’s really exciting,” said Prof Giovanna Mallucci, from the MRC Toxicology Unit in Leicester.

She wants to start human clinical trials on dementia patients soon and expects to know whether the drugs work within two to three years.

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