Midbrain Atrophy in Parkinson’s, Alzheimer’s and Multiple Sclerosis

Brain-sagittal-GraysThe midbrain is the smallest structure in the brain and is positioned on top of the brainstem. In the picture to the right, it can be seen located between the thalamus and hypothalamus of the diencephalon above, and the pons and medulla of the lower brainstem below. The thalamus located on top of the midbrain, forms the walls of the third ventricle. Among other things, atrophy of the thalamus and enlargement of the third ventricle (ventriculomegaly) have been associated with multiple sclerosis (MS).

In contrast to the ventricles, which are in the core of the brain, the cisterns surround the midbrain. Enlargement of either can be a sign of atrophy. Enlargement of the cisterns along with atrophy of the midbrain has been associated with variations of Parkinson’s called progressive supranuclear palsy, vascular Parkinson’s, vascular dementia, multisystem atrophy, and an Alzheimer’s variation called Lewy-body dementia.

Some of the characteristics of vascular Parkinson’s and vascular dementia overlap. Both conditions are associated with a more frequent occurrence of brain atrophy, white matter lesions and a predominance of motor symptoms, such as gait disturbances. Several clinical features of vascular Parkinson’s, including early postural instability, pseudobulbar phenomena, and predominance of lower body signs, further suggest that vascular Parkinson’s may be associated with atrophy of the brainstem.

In addition to the neurodegenerative conditons above, atrophy of the midbrain has also been associated with MS. More often, however, MS is associated with enlargement of the cerebral aqueduct of the ventricular system, especially the upper portion located adjacent to the third ventricle, mentioned above. In any case, researchers now suspect that the midbrain is particularly sensitive to neurodegenerative conditions. They offer no explanation, however, as to why it is particularly sensitive. One possible explanation, may be because of its exposure to cerebrospinal fluid (CSF) hydraulics in the ventricular system and cisterns.

The midbrain is surrounded by cisterns filled with CSF. CSF also passes from the third ventricle through the cerebral aqueduct in the midbrain to the fourth ventricle below. The portion of the midbrain located behind the aqueduct is called the tectum. The portion in front is called the tegmentum. The midbrain is associated with sight, sound, motor control, the sleep-wake cycle, alertness and temperature regulation. It also contains pathways for communication and coordination between the higher and lower centers of the brain, brainstem and spinal cord including the long motor tracts that descend to the cord to supply the muscles and the sensory nerves that deliver information from receptors in the body to appropriate centers in the brain.

midbrain-axialAs shown in the sketch of the midbrain on the left, the cerebral aqueduct is surrounded by gray unmyelinated nerves called the periaqueductal gray matter, which contains the reticular formation of the brainstem. The reticular formation contains functional cell groups that are important for control of eye, head, or lid movements. The mesencephalic reticular formation is primarily involved in the control of vertical gaze. Vertical gaze is sometimes affected in Parkinson’s disease and MS. The dark gray band on the ventral (front) side of the midbrain is the substantia nigra which produces a neurotransmitter called dopamine. Atrophy of the substantia nigra and decreased dopamine production are hallmark signs of primary Parkinson’s disease. Among other things, decreased dopamine production causes resting tremors in Parkinson’s.

There are many different types of midbrain syndromes. Two well known midbrain syndromes, called Parinaud’s syndrome and dorsal midbrain syndromes, have been associated with Parkinson’s disease, dementia and MS. Dorsal midbrain syndromes are associated with difficulty looking up, diplopia, blurred vision, oscillopsia (symmetrical eye tremors), as well as other accompanying neurological symptoms. It is sporadic. The causes are obstructive hydrocephalus, hemorrhages in the midbrain, MS, AV malformations, trauma, and compression, such as from pineal tumors.

Hummingbird-sign2-radiopaediaAtrophy of the midbrain is most commonly associated with progressive supranuclear palsy, mentioned above. The atrophy causes a characteristic deformation of the midbrain that radiologists refer to as the hummingbird sign when viewed from the sagittal view (side) because it looks like a small bird with a large beak, as seen in the brain scan on the left. The brain scans on the left and below are used with permission from a collection by Dr. Frank Gaillard of Radiopaedia.com. The hummingbird shape is seen at the top portion of the long, dark gray structure (brain stem) in the middle of the brain. There is a long, thin, curved beak-like projection in front and a big round structure below, which is the pons portion of the brainstem. The hummingbird sign is also called the penguin sign. In either case, the beak is the most telling feature of atrophy of the midbrain. The beak is part of the tectum on the dorsal (rear) surface of the midbrain. The tectum contains important nerve centers related to the control of eye muscles and sight. It also contains nerve centers related to sound.

When viewed from top to Mickey-mouse-signbottom looking down on the brain, which is called an axial view, the midbrain appears compressed front to back in a characteristic deformation. Radiologists call it the Mickey Mouse sign because it looks like a small round face with a little black nose and big round ears located in the center of the MRI on the right.

Progressive supranuclear palsy, also known as Steele-Richardson-Olszewski syndrome, is a rare disease. It gradually destroys nerve cells in parts of the brain that control eye movements, breathing, and muscle coordination. The loss of nerve cells causes palsy, or paralysis, that slowly gets worse as the disease progresses. The palsy affects the ability to move the eyes, relax the muscles, and control balance. The initial symptoms in two-thirds of the cases are loss of balance, lunging forward when mobilizing, fast walking, bumping into objects or people, and falls. Other common early symptoms are changes in personality, general slowing of movement, and visual symptoms.

Signs of progressive supranuclear palsy include: supranuclear ophthalmoplegia, rigid neck spasms called dystonia, Parkinsonism signs and symptoms, pseudobulbar palsy (difficulty swallowing and speaking), behavioral and cognitive impairment, imbalance and difficulties walking, as well as frequent falls. Atrophy of the midbrain appears to be more characteristic of vascular Parkinson’s and progressive supranuclar palsy than primary Parkinson’s which is typically associated with specific degeneration and atrophy of the substantia nigra. It’s also less severe in vascular Parkinson’s compared to progressive supranuclear palsy.

The cause of atrophy of the midbrain in Alzheimer’s and Parkinson’s disease, as well as enlargement of the cerebral aqueduct of Slyvius in MS is unknown. In addition to the aqueduct, MS is also associated with enlargement of the third ventricle that adjoins and drains into it. Ventriculomegaly and an enlarged cerebral aqueduct are signs of hydrocephalus. In contrast to the ventricles and cerebral aqueduct, enlarged cisterns are not necessarily a sign of hydroceplalus if not accompanied by enlargement of the ventricles. On the other hand, hydrocephalus is caused by obstruction to CSF flow that results in an increase in volume. One of the most likely places for blockage of CSF flow to occur is in the foramen magnum and upper cervical spinal canal. Blockage of CSF flow between the cranial vault and spinal canal can cause an increase in volume in the cisterns and subsequent compression of structures they surround such as the midbrain. Decreased blood flow and chronic ischemia may also play a role in atrophy of the midbrain but that’s another topic that will be discussed in future posts. In any case, malformations, misalignments and chronic deformation of the upper cervical spine may affect blood and CSF flow in the brain leading to chronic ischemia, edema and normal pressure hydrocephalus resulting in neurodegenerative conditions and diseases.

For further information on the role of the midbrain in neurodegenerative conditions, visit my website at www.upright-health.com. The cause behind many of the conditions above is discussed in my book, “The Downside of Upright Posture”. Information, of which, can also be found at the website.

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About uprightdoctor

I am a sixty year old retired chiropractor with considerable expertise in the unique designs of the human skull, spine and circulatory system of the brain due to upright posture, and their potential role in neurodegenerative diseases of the brain and cord. I have been writing about the subject for well over two decades now. My interests are in practical issues related to upright posture and human health.
This entry was posted in Alzheimer's, diplopia, multiple sclerosis, nystagmus, Parinaud's syndrome, Parkinson's, progressive supranuclear palsy and tagged , , , , , , . Bookmark the permalink.

23 Responses to Midbrain Atrophy in Parkinson’s, Alzheimer’s and Multiple Sclerosis

  1. shawn says:

    fantastic book, its given me even further insight to what i have suspected to be reason for my neurological disorder. i look forward to your follow up book :) but until then, any morsils you can toss concerning what i should be doing in the mean time to ease my symptoms would be greatly appreciated. i live in the oakland california area, just in case you have a chiropractor you recommend in the area.
    my disorder has yet to be diagnosed, as my mri (laying) is regular, except for an artery that is closer to the brainstem than normal. negative blood tests (Mgravis) and my neurologist are now at a lose. i have double vision, co-ordination issues and slurred speech less frequently. both the later symptoms being daily……in case u are interested. i can give further insight if ur intersted.
    thanks a ton.

    • Hello Shawn,
      I am all ears if you wish to describe more about your case here. If you purchased my book you also received my email address if you wish to discuss your case privately. The symptoms of loss of coordination and slurred speech suggest possible structural strains acting on the posterior fossa and base of the skull. The double vision is due to loss of conjugation of the eye muscles. The control center for conjugation is in the midbrain. The muscles for eye movement originate in the upper brainstem and pass through the cavernous sinus of the cranial vault and out through the orbital fissures where they connect to the eye. Intracranial pressure problems can affect the conjugation centers in the midbrain. The cranial nerves that control eye movements can get strained by displacement of the brainstem in the cranial vault. Displacement and tension of the brainstem can occur due trauma to the upper cervical spine. There may be some specific upper cervical, craniosacral and other doctors in the Oakland area who can help you.

    • shawn says:

      thanks a bunch. i will crack open my book to retrieve your email address and send you a private email to give you more of the specifics.

  2. shawn says:

    i couldnt find your email anywhere in the book. i will just have to lay out my my story here. but, for future reference, if you could let me know where in the book it is located it would be appreciated.

    MY TESTS
    - MRI – showed no abnormalities except for an artery closer to the brainstem than normal. he did not seemed concerned.
    - X-Ray of cervical spine – showed degeneration of 2 of my discs. unfortunately i dont remember which ones. the chiropractor speculated i injured my neck about 7 years prior. which coincided to when i was doing jui-jitsu and injured my neck by being placed in too many triangle chokes. i didnt think it was anything serious then, just a few weeks rest and it was ok.
    - Blood Tests – ruled out myostemia gravis
    - X-Ray of thoracic and lumbar spine – showed i have levoscoliosis to 7 degrees, which was said to be not a big deal, but for me my midback is a constant bother. lower back showed lack of normal curvature.
    - neruologist ruled out all other neuro. diseases and is at a lose.

    SYMPTOMS
    - vision: daily double vision, delayed focus (always), flippin vision (like how the old tvs would do until you adjust the knob underneath),

    - co-ordination and balance: daily (to varying intensities) often made worse with prolonged sitting or standing of over and hour (particularly standing).
    - slurred speech:

    • Hello Shawn,
      You are an interesting case. You clearly have brainstem/cerebellar issues. The double vision, delayed focus and flipping vision you describe is due to mechanical stress affecting the conjugation control centers in the midbrain. The coordination problems and slurred speech suggest are due to problems in the posterior fossa. Your history of Jiu Jitsu makes me suspect whiplash injuries. Whiplash injuries can cause structural strains called misalignments by chiropractors. Structural strains of the craniocervical junction can cause deformation of circulatory and CSF tunnels between the cranial vault and spinal canal resulting is ischemia, edema and hydrocephalus. Structural strains of the spine also causes displacement of the brain and cord in the cranial vault and spinal canal called ectopia. Displacement of the tissues of the brain causes tension, compression and shear stresses. Displacement of the brainstem toward the foramen magnum can also affect blood and CSF flow between the brain and cord. You need to have you spine, especially your upper cervical spine checked and corrected. You also need to have someone look at the scoliosis. Patients with scoliosis are predisposed to ectopia, Chiari malformations and coning of the brainstem into the foramen magnum. Scoliosis is also associated with tethered cords. Structural strains in the lower spine can cause, contribute to or maintain structural strains in the upper cervical spine and base of the skull.

      My email address isn’t in the book. It was sent to you when you ordered it.

  3. shawn says:

    sorry, screen is doing some wierd scrolling thing. so, i had to break it up.
    -slurred speech: less common. but, difficulty speaking after exercising.
    -fatigue, constipation, brain fog

    -balance is often made worse due eating also, particularly if its a larger meal. i was wondering what u make of that?
    -also i had an “episode” a few days ago where i became ill after eating something and it just churned in my belly for an entire 24 hours. i eventually got a fever and all my neurological symptoms list above were exascerbated to almost incapacitating extremes. literally could not form a syllable for an entire day, had to use the wall to walk carefully and could not place my soap back on the sink due to hand jerking around. this is apparently out of the scope of your book, but i was wondering what do you make of that?

    do you recommend any chiros that use specific upper cervical spine technique in my area? i dont want you to empty the contents of your next book out here, but could you offer up anythings that i could be doing myself to increase the circulation to my brain? or can you put a rush on that book of yours or something ? :) were hurting out here doc

    thanks again,
    shawn

    • The fatigue, brain fog and slurred speech suggest possible problems with intracranial pressure. Eating increases pressure on the abdominal veins which is transmitted to the vertebral veins in the spinal canal which transmit the pressure to the dural sinuses in the brain similar to a Valsalva maneuver. The hand jerking around sounds like extrapyramidal problems in the basal ganglia that may likewise be related to pressure problems. You need to reduce the structural strains on the base of the skull to restore proper blood and CSF flow and pressure in the brain.

  4. shawn says:

    oh! and levoscolios to 7 degrees. i know they say thats not much. but, it gives me grief on a dialy basis. i have to quit my job because of it.

    • The lower spine can cause or contribute to structural strain in the upper cervical spine. They can also maintain structural strains in the upper cervical spine and prevent or limit reduction of the strain if they are not addressed properly.

  5. shawn says:

    and vision is made much worse with running. its flips like crazy. i do however run with at forward leaning position once im fatigued…..sorry :)

  6. shawn says:

    i found your book by doing an amazon search of “circulation, brain”, as i was thinking brain circulation could be a cause of my problem. this was before i was even aware of you and your blog. so, my girlfriend at the time bought your book for me for xmas off of amazon. she only gave me the book, no extra anything with your email.
    so, would you say my next best move would be to go see a chiropractor? since you havent mentioned it i assume you dont have a chiro you recommend out my way. so, i am curious as to how much you charge and how long do you think it would take to alleviate my symptoms? i ask you this because me flying to NY and sleeping in the bushes and eating gyros everyday is not out of the question, if it means i can have my life back to normal.

    • Shawn,
      It may or may not work but it won’t hurt and it is well worth a try to see a chiropractor as I suspect you have a whiplash injury from Jiu Jitsu. I have a lot of background in martial arts with black belts in several style of karate. I also did a fair amount of Judo an Jiu Jitsu when I was younger and had a Judo team for patients when I was in clinic. All martial artists, Judoka and wrestlers need regular care for frequent injuries and structural strains, the same as any contact sport. I would suggest that your next move would be to see a chiropractor, but you need someone extra-special. Hopefully, there will be someone in the Oakland area. If not then we can discuss you visiting NY so I can take a look at you myself. I will contact you. If we get lucky maybe we can get your life back.

  7. shawn says:

    and thanks again for the speedy responses. its nice to be making some progress after having neurologists coming up with nothing for years.

    • Your welcome. Neurologists don’t get it because they aren’t connecting the dots and can’t see what is starring them in the face. I have a pretty good idea what is causing the problem. Now we need to see if it can be corrected.

  8. Angela Backus says:

    Hello Dr. Flanagan,

    I have written you before, about a year ago now, I have been seeing a Nucca in BC. I was doing much better so much so I had finally worked my way up to not seeing him for 2 months and felt great. I went in to see him on Jan 10th and told him I was doing great I was exercising more than I have in 10 years and just wanted to keep my file open (so I would not have to pay for more x-rays) and he insisted on adjusting me. I left his office that day and within a half hour my neck kind of cracked/snapped and instantly my symptoms returned. I am in so much pain my muscles are very weak and I am numb on that side again. I have been back 3 times since and more x-rays were done, and now my c1 is off balance on the left side where as before it was the right side.
    The last time I wrote you I explained that I have MS and I have had CCSVI done 2x, what I did not tell you was that during the first procedure I could here the bones in my neck moving, after the surgery the doc told me I had severe scarring at C6, this made sense to me because I had an MRV done before the procedure that showed narrowing at C6. I am terrified now and I am unsure what to do? Of course the Dr. is saying it was not what he did but instead it happened because of the way my body reacted. I can feel in my neck that I am out on the lower right side. I am unable to sleep, hold my bladder, exercise, properly digest, my balance is off, severe night sweats and I have my persistent dull headache back. All these symptoms have been gone since my first angioplasty in Dec. 2010, the reason I had the second procedure was because my heat intolerance had returned as well as balance and muscle weakness. My Email is in the details please email me. I do have a digital copy of my MRV report and if I knew how to put the CDs online I have both procedures on CD. I truly look forward to your reply as right now I am afraid and a bit frustrated as all of this has cost me well over 25,000 and at this moment I feel as if I have thrown that money away.
    Sincerely, Ang

    • Hello Angela,
      It is my opinion that the venoplasty can be helpful in improving drainage of the brain by acting as a siphon. The dilated jugular vein, however, can eventually decrease in size and the effect wear off causing a return of symptoms. While stents are more durable than venoplasty they have other problems and they can become clogged. In any case, from what you report, I suspect that you may have a small posterior fossa with a Chiari one or Chiari zero type malformation blocking blood and CSF flow between the cranial vault and spinal canal. The degenerated disc in the lower cervical spine may be compounding the problem. I would like to know what may have caused it. It may be related to the cause of your condition. I will contact you.

  9. S says:

    actually please just scrap my comments i read that I would receive your email upon purchase!

  10. S says:

    hey doc it says you wont accept payment from non-us paypal could you email me?

  11. S says:

    Hi Doc
    Been trying to get in touch by email but have received no response

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