In 2003, Heiko Braak identified a pattern of Lewy body deposition, in the synucleinopathies (the term that is given to any disease that results in the accumulation of alpha-synuclein proteins), which include Parkinson's Disease (PD), Multiple Systems Atrophy (MSA), Progressive Supra-nuclear Palsy (PSP) and Dementia (LBD).
The pattern that he identified has been termed the Braak Staging of Lewy Body inclusions. More current research shows that Lewy Body pathology can spread from one area of the nervous system to another, and it's conceivable that this happens in a prion-like fashion. There are also some studies that show alpha-synuclein is not only just an intracellular protein but is extracellular as well, which could explain to some degree, the progression to other areas of the brain.
The first three stages of Braak's staging, are largely "asymptomatic" to the uninformed individual.
In stage 1, inclusion bodies begin accumulating in the olfactory bulb (which is the first step of the smell pathway) and a part of our brainstem called the Vagus Nucleus. Symptoms at this point may include a change in the ability to smell and taste, as well as a constellation of symptoms we call autonomic symptoms, which are often casually related to "aging". The symptoms may, or may not include: constipation, sexual dysfunction, dry eyes, dry skin, light-headedness, high blood pressure, insulin resistance, swelling of the hands and feet, bladder dysfunction, an increase in heart rate or arrhythmia, dizziness when getting out of a chair or bed, etc.
In stage 2, inclusion bodies begin to form in a part of our brain stem called the locus ceruleous, and vestibular gain setting nuclei. The result of inclusion body formation in these areas leads to difficulty with arousal, and wakefulness, and excessive sleepiness. The vestibular gain setting nuclei participate in the maintenance of balance, posture, motion tolerance, as well as eye movement. Involvement of a large brainstem nucleus called the nucleus gigantocellularis can begin to cause tightening and decreased mobility of the neck.
In stage 3, as alpha-synuclein ubiquitinates and deposits in the midbrain substantia nigra, some of the classical symptoms associated with Parkinson's disease begin to emerge. The compacted portion of the midbrain produces dopamine to facilitate motor function, while the net-like, or the reticular portion of the midbrain produces an inhibitory neurotransmitter called GABA, which has a role in both body movement, and fast eye movements. Typical symptoms at this point time are a slowness of movement, usually on one side of the body first, a decrease in motivation, changes in sleep patterns and dreams/hallucinations, smaller handwriting, slowing of walking speed, difficulty walking down stairs, blurred vision, joint stiffness, and more. It is around this time that a Parkinson's expert often first identifies a possibility of the PD diagnosis, which is usually about 7 years after stage 1. At the first appearance of motor signs, it is estimated that about 30%-50% of dopamine neurons have been lost.
When the mesocortex, which is a part of the brain between the midbrain and the forebrain, is affected, an individual will begin having changes in emotion. Often this results in the lack of impulse control, anxiety, depression, slowing of speech, avolition (lack of motivation), and flat affect. These are all signs of stage 4. Often in stage four, a tremor may emerge in one hand. It is in stage 4, usually about 10 years after stage 1, that general practitioners start to recognize the signs of Parkinson's disease in their patients.
In the final two stages of Parkinson's disease, proteins begin depositing in the sensory association areas of the brain (Stage 5), followed by the supplementary and primary motor areas (Stage 6), leading to slowness, of movement, rigidity, stooped posture (termed camptocormia) slowness of movement (bradykinesia), freezing (akinesia), tremor, slowness of thought (bradyphrenia), difficulty or slowness in swallowing (dysphagia), weakness of voice (hypophonia), and eventually dementia.
Although Parkinson's Disease is not a fatal disease, meaning that individuals do not die of Parkinson's Disease, the effects of the disease can lead to morbidity and mortality, with falls being the number one most common (68.3%) and preventable cause of death in Parkinson's afflicted individuals.
There is no standard imaging for Parkinson's Disease, although DaTscan, a variation of SPECT scan that can observe dopamine transport, has shown to be promising. The diagnosis of Parkinson's Disease currently lies in the clinical examination. Authors have indicated that the sensitivity and specificity of accurate diagnosis by a trained and experienced clinician is (Jenkins 2012) 95% and 98% respectively. At this point in time, DaTscan can confirm or at least increase the confidence of an accurate diagnosis.
Identifying a problem without suggesting a solution is almost as bad as not knowing about the problem at all. Since 1978, the Carrick Institute for Graduate Studies has been training doctors around the world to be able to identify Parkinson's Disease quickly, effectively, and early, so that various non-pharmaceutical interventions can improve the quality of life, safety, and well-being of individuals developing, or with Parkinson's Disease.
The doctors at Plasticity Brain Centers in Orlando, FL are all #CarrickTrained in neurological rehabilitation and management of individuals suspecting or diagnosed with Parkinson's Disease. If Orlando is too far for treatment, you can still contact Plasticity Brain Centers and inquire about doctors in their NeuroNetwork around the world. Alternatively, you can also look on ACNB.org for a Carrick Trained Chiropractic Neurologist near you.
In upcoming posts we will discuss a clinical grading scale termed the UPDRS (or United Parkinson's Disease Rating Scale) that has been developed to measure the progression or regression of Parkinson's Disease. We will also discuss non-pharmaceutical individualized patient-centered applications for Parkinson's Disease, and other neurological conditions.
Stay tuned to the #TalkNeuro Blog!
Further Reading and Reference:
Heiko Braak et al. Staging of brain pathology related to sporadic Parkinson’s disease. Neurobiology of Aging. 2003; 24:197-211
Heiko Braak and Kelly D. Tredici. Eds. Neuroanatomy and pathology of sporadic Parkinson’s Disease. Springer-Verlag Berlin Heidelberg; 2009.
Jenkins, Mary E. eds. Neurology: an evidence-based approach. New York, NY: Springer; 2012.