Motor Rehabilitation after Stroke


Motor rehabilitation is a growing field of interest as ancient ideas of localization are being forgotten and new concepts of brain plasticity are being embraced. “The term plasticity is often used when mechanisms of recovery after focal brain injury are considered”[11] Dr. Michael Merzenich’s life work is partially responsible for dismantling the once strongly held notion of localization-structure and function of the brain is rigid and unchanging. Localization was a theory develop in the 1930s and was developed when the brain was immaturely mapped out using. With modernized neurotechnology instruments available i.e. microelectrodies, neuroimaging instruments and neuroatonimcal tracers, evidence for brain plasticity has challenged the rigid notion of localization. While, the neuroscience community may still be hesitant to completely embrace all concepts that are implied with brain plasticity the work of people such as Dr. Merzenich highlight the complexities and seemingly limitless potential of the brain and nervous system. Researchers and scientists, alike, have gradually made tremendous advancements regarding brain rehabilitation and accord with bodily functions. A dilemma in the neuroscience community, that has been the subject of countless studies and experiments, neurorehabilitation is on the brink of incredible new discovers. It has made remarkable strides concerning neuronal pathways and the need for new pathways and strategies to create new pathways in stroke victims to introduce or strength rehabilitation is an area that is quickly receiving popularity renown. In stroke patients there is hope to regain and strengthen motor functions due to plasticity.

1. Brain Injury
2. Results From Stroke
3. Technology & Therapy
-Mapping & Imaging
-Axonal Regeneration
4. Brain is Plastic
5. Motor Function & Pathways
6. Therapy Options
7. Tension in the Field
8. Summary
9. References & Suggested Readings
10. Study Questions

Fig. 1
Fig. 1

Brain Injury

Brain rehabilitation is best understood when first considered in the context of injuries that the brain may suffer from during a stroke, a head physical trauma, or a physiological effect from a mental health condition. Physical trauma, we know, can cause both immediate and gradual signs of the brain having sustained an injury. There are two types of stroke that can occur: ischemic stroke- when supply of blood to a part of the brain is suddenly blocked or cut off and hemorrhagic stroke-when blood vessels suddenly burst in the brain [5].

When an area of the brain is hindered from receiving oxygen those cells die and it results in lesions [4]. In a special report for the American Heart Association, Dr. Johansson, details the compensatory actions of the brain to function after certain areas of it have been damaged or lost to cell death completely. The infractions on bodily functions are the effects of a stroke that rehabilitation attempts to compensate for [9].

Fig. 2
Fig. 2

Results from Stroke

The following physiological issues may occur after a stroke:

1) problems with motor control, including paralysis or weakness on one side of the body, swallowing, walking, posture, or balance, and loss of continence; 2) unusual physical sensations such as pain, numbness, or tingling, or the inability to feel touch, pain, or temperature; 3) difficulties with speech and language; 4) problems with thinking, planning, memory, and judgment; and 5) emotional distress such as feelings of sadness, grief, anxiety, and depression.

After brain bleeds occur and parts of the brain experience restricted blood flow, tissue and brain cells die-dramatically injuring and reshaping cortical mapping and functions.

Fig. 3
Fig. 3

Fig. 4
Fig. 4

With brain bleeds caused by a forced impact to direct contact of the brain by a foreign object entering or penetrating the brain both the form and functions of the brain is heavily impacted. In research and case studies, it’s found that when blood clots and bleeds cause damage in the following areas the subsequent issues typically arise. The brain then needs to establish new pathways or strengthen secondary or tertiary pathways to regain functions such as talking, moving, and coordinating in efforts of rehabilitation.

The following figure shows the resulting motor effects affects caused by that pathway and physiological damages from stroke.

Fig. 5
Fig. 5

Technology & Therapy

Brain Mapping & Neuroimaging
Doctors and researches use computerized tomography, magnetic resonance imaging, scans such as PET, SPECT, EEG to assist in first assessing initial damage and organizing a plan for rehabilitation. A gateway into the rehabilitation process occurs when neuronal connections and mapping in the cortex are used to asses victims of brain injury with lesions. Dr. Barbro Johanasson in “Brain Plasticity and Stroke Rehabilitation” discusses the use of neuroimaging in guiding researchers in further understanding how to better help patients [4]. The importance of gathering as much information for an intervention plan is key in revitalizing areas and or cultivating new pathways.

Axonal Regeneration
Johansson details the compensatory actions of the brain after a stroke and one of those actions are the regeneration of axons after a stroke [4]. This is an example of a unilateral lesion with ipsilateral effects. In a stroke compensatory sprouting occurs and in the figure below (6) we see an example from the corticospinal tract (CST). For stroke patients who experience unilateral lesions their corticospinal motor neurons-that are shaded in red, cause the degeneration of the entire CST projection from that side. Evidence of the brain working to rehabilitate motor functions is seen in the unlesioned CST track sending sprouting fibers-shaded in green, contralaterally. This occurs in the brainstem at the red nucleus and at segmental spinal cord levels. This pathways attempts to compensate for the lost CST on the injured side of the brain. Treatment to promote axonal regeneration for all descending pathways may use Nogo-66 receptor blockers, anti-Nogo-A antibodies, or inosine. These enhance regeneration via increasing plasticity potential in the sprouting response of additional axons [4]
Fig. 7
Fig. 7

Fig. 6
Fig. 6

Evidence of the brain working to rehabilitate motor functions is seen in the unlesioned CST track sending sprouting fibers-shaded in green, contralaterally. This occurs in the brain stem at the red nucleus and at segmental spinal cord levels. This pathways attempts to compensate for the lost CST on the injured side of the brain. Treatment to promote axonal regeneration for all descending pathways may use Nogo-66 receptor blockers, anti-Nogo-A antibodies, or inosine. These enhance regeneration via increasing plasticity potential in the sprouting response of additional axons [3].

Neuronal Connections for Motor Functions[1][10]

The cerebral cortex’s purkinje cells are responsible from transmitting impulses to the output nuclei-deep cerebellar nuclei. Each purkinje cell has different axons exiting the cerebellum and entering the red nucleus, thalamus, vestibular nuclei, and/or the reticular formation.

-The flocculonodular lobe[8]
The afferent pathways associated with the flocculonodular lobe originate from the vestibular nuclei and travel along the inferior peduncle and to the flocculonodular lobe to be processed. This region receives input to convey signal related to retinal image slip, head movement, and eye movements-important in somatosensory cortical damage[10]. The vestibular nuclei innervates in the flocculonodular lobe and it has vestibulospinal and vestibule-ocular projection that descend and ascend in the medial longitudinal fasciculus (MLF). Axons in MLF innervate the motor neurons that control the axial muscles and others such as external ocular muscles. [10]

-The Interposed Nuclei
The intermediate hemispheres in the IN process information from the proximal somatosensory, auditory information, spinal tracts, and visual information. The red nucleus is the origin of the rubrospinal tract that decussates-the interposed nucleus influences ipsilateral motor activity. It also contains the globos and emboliform nuclei. The output from the globos and emboliform nuclei travel along the superior peduncle and decussate to the contralateral red nucleus.

-The Dentate Nucleus
The dentate nucleus receives input from the lateral hemispheres that are corticopontine cerebellar inputs-the information for motor planning of a requested movement. Corticopontine is coming information from the cortical area of the brain-PMA and M1, which goes through the pontine nucleus to enter the cerebellum through the middle cerebellar peduncle. Image 5 : the corticopontine fiber is in green showing the pathway to the cerebellum. After the lateral hemisphere processes this information it is passed to the dentate nucleus. The efferent axons leave the cerebellum through the superior peduncle. It synapses in the contralateral ventrolateral nucleus of the thalamus. Thalamic nuclei projects to the motor cortex so the dentate can control and influence the motor activity. Tracts descending decussate thus the dentate nucleus also influences ipsilateral motor activity.

-Fastigial Nucleus
This is a medial nuclei that receives input from the vermis (cerebellum). The vermis receives input from the vestibular system, the proximal somatosensory, the auditory, and the visual system. The vermis then sends the processed information to the fastigial nucleus. Its output to the reticular formation travels through the inferior peduncle to the vestibular nuclei and out of the cerebellum. From the vestibular nuclei it goes ipsilateral and contralateral. After the vestibular nuclei the impulse stimulation travels along the vestibulospinal tract to ipsilateral motor neurons that influence extensor muscles. The axons synapse at the reticular formation influence ipsilateral motor activity in segments along the spinal cord through the reticulospinal tract.

Brain is Plastic
Plasticity refers to the ability for the brain to change to utilize different pathways in a systematic manner over time [11]. Similar to learning, the brain changes and is changing all the time. Evidence of dendrite lengthening in several animal studies show that the physical brain may change due to improved or additional functions. Synaptic connections compose the cortex and its several parts and sections. The fundamentals of localization are helpful in learning the lobes and sections of the brain-such as the sections in the image below.

Fig. 8
Fig. 8

Learning is also evident do to synaptogenesis-the synaptic activity within the nervous system. In addition, mechanisms of change are seen in the long-term potentiation and long-term depression of synaptic efficacy in the hippocampus and neocortex-where high ordered thinking is associated with. The primary motor and premotor cortex and the cerebellum have connections and pathways that are effected by new axonal, dendritic growth and strengthening pathways via pharmaceutical enhancers or practice, and rehearsal. Cortical maps are too effected by such elements such as pharmaceutical manipulations and lesions where brain structure and function can be seen to interact and correlate

Motor Function and Pathways[8][12]

In rehabilitation in order to perform accurate and coordinated movements and the pre-motor cortex, primary motor cortex, cerebellum and affiliated descending and ascending pathways must be assessed and treated after a patient suffers a stroke.

Integrating Pathways receive input from proprioceptive inputs, sensory inputs, and visual inputs. Integration occurs in the post parietal cortex in areas 5 and 7. Here, sensory cortex extensive inputs terminate.

-Descending pathways from cortex include corticobulbar and corticospinal from the following 3 areas:

--Primary Motor Area: (M1; Brodmann’s area 4) in pre-central gyrus
--Pre-Motor Area (PMA; Brodmann’s area 6) in frontal lobe, anterior to M1
--Supplementary Motor Area (SMA; M2) on medial surface of frontal lobe

-Voluntary Movements are facilitated and executed primarily through the Motor Corex (M1) through the circuit of the basal ganglia. The following figure demonstrates the intricacies of this pathway that has both an indirect and direct pathway. Stroke effects both pathways (descending and ascending). Neurotransmations such as glutamate and dopamine are involved in the synapses in the basal ganglia-collection of five major nuclei groupings. *Forced movement therapy has been found to activate weakened areas of the motor cortex that have been damaged from a stroke in areas if the motor cortex[2].
Fig. 10
Fig. 10

Fig. 9
Fig. 9

-Somatotopic representation of muscles to perform movement are found M1, PMA and SMA. The following pictures below offer two ways to view the cortex label and withthe bodily somatotopic representation.
Fig. 12
Fig. 12

Fig. 11
Fig. 11

-Neurons are active in movement planning and are involved in creating the motor plan from incoming somatic sensory in the post central gyrus to participate in the basal ganglia loop.

-PMA output of neurons from the somatic sensory cortex via corticubilar and corticospinal tract are effected with areas in this part of the cortex loose its ability to send or receive stimulation (input/reaction).

- Prefrontal cortex, SMA & PMA, creates the plan to move, conversion of intention to actual movement and plan selection occurs and finally the movements are execute via the primary motor cortex. In motor rehabilitation therapies, this is the ultimate goal, to establish a plan and execute using viable cortex and cerebral involvement.

Forced Limb Therapy
Forced limb therapy is moving a weak or unable of moving body part repeatedly to prompt stimulation and rehabilitation on the cortical and spinal level. The main idea of this therapy is to stimulate the associated axons, dendrites, and neurons that have been effected by brain damage from a significant brain injury-i.e. a stroke. Many have said that this type of pressure and stress on patients who have recently suffered through a stroke is inefficient and has the potential to cause harm to the patient. However, this counter-intuitive act to forcefully use limbs that have been affected in stroke victims has shown signs of promoted brain plasticity. A neuroanatomical tracer was used to track behavioral recovery in stroke victims in a study done on rats by researchers at China Medical University [7]. Increased levels of cAMP and neurons were found after forced limb use. This therapeutic option provided a stimulate at a basic level that poured out into increasingly complicated levels that resulted in improved bodily functions such as movement, or improved speech.

Constraint-Induced Movement Therapy

Constraint-induced movement therapy of Dr. Edward Taub is controversial and described to be particularly successful in aiding stroke victims as they regain their ability to move and speak. However, this success was not immediately celebrated and embraced. Dr. Norman Doidge shares in, The Brain that Changes Itself that Taub used monkeys to demonstrate the effects of damaged sensory nerves caused by lesions from strokes [2]. The monkey was then forced to have its good arm in a sling and restrained. Through therapy, the monkey was forced to use its damaged limb and develop new, use other neuronal pathways-. Adults who participate in the Taub Clinic receive a two-week long intensive rehabilitation program that uses behavioral techniques to promote use of their injured limbs while their healthy ones are restrained. Constraints were also provided for those who suffered from the speech-related effects of a stroke. Participants were given simple rules that prompted their brains to form new connections with words they sought out to use or say. The structure of an intensive and “forced” methodology is one that received scrutiny and Dr. Taub was questioned and tried on behalf of animal rights..

The ethical issues, that Doidge details, plagued Taub and delayed the sharing of such great advancements he community at large. Other ethical problem that the literature is aware of concern the environment that stroke and brain injured patients are in. However, in the following clip, we see that this therapy has come a long way and has been the solution for people seeking Independence and regaining basic function.
*For a more in depth look into Taub's methods, please watch this clip-an instructional introduction to constraint induced movement therapy for people with Stroke*

Task Specific & Behavioral Manipulation Therapies
Controversies, however, are not entirely present in the area of task specific and behavioral manipulation in the rehabilitation process of stroke and brain injured patients. An interesting form of therapy that embodies cognitive and physiological improvements is called task specific physiotherapy [6]. This therapeutic option is coupled with behavioral manipulation to spur bodily functions and neural plasticity in stroke patients in, Modulation of Neural Plasticity as a Basis for Stroke Rehabilitation. Dr. Marcela Pekna a neuroscientist in Sweden has established experimental models and clinical studies in support of neurorehabilitation. Regional cell death is explored and the phenomenon of plasticity is observed through the development of new neural pathways in her work with stroke patients. Rehabilitation is said to be enhanced by behavioral manipulations and combination with adjuvant therapies that stimulate the endogenous neural plasticity [6].

*More Surgical/Non-Invasive Options*
Dr. Marcela Pekna and her research team have also brought attention to both surgical and non-invasive interventions that would assist in neurorehabilitation. The history of surgical intervention was for brain injuries can be immaturely connected to the work of Dr. Freeman and lobotomies in the mid-1900s. However, Pekna speaks of contralesional axonal remodeling of the corticospinal system, in her report on plasticity that may occur spontaneously [6]. Further research is in the process of understanding how to artificially spur this remodeling process by way of surgical intervention. Non-invasive interventions are also an option in the journey of brain rehabilitation. “Noninvasive brain stimulation can be performed using repetitive transcranical magnetic stimulation (TMS) and transcranial direct current stimulation” Pekna reports to support the recovery of cognitive and motor functions including upper limb movements [6].

Tension in the Field

The nature of this field is one that unique in that it pushes pre-set limitations that have established for years and introduces the abstract concept of plasticity, specifically brain plasticity, which is not yet accepted by all [2]. This creates a tension between researchers, ethic boards, and media perception on progressive research designs that seek to do and uncover the mysteries of the brain. Such a dichotomy of advancements in a rigid and hard to change world of understanding, provides room for controversial methods and concepts to be present. In the field of rehabilitation by way of brain plasticity is certain therapeutic methods have come under scrutiny in the media and also the literature.


Technological advances have made it possible for innovative motor rehabilitation therapies to take shape, be tested, and prove effect for stroke patients. The human brain and body is cable of doing such great things and it is evident in axonal regeneration, and stimulation being interpreted and expressed in “new” cortical areas. The damage from stroke may be irreversible in some cases, however, the future is not bleak for the advancements in neuroscience for rehabilitation. Each motor pathway may be effect by a stroke. The cortex, cerebellum and brainstem are such complex and intricate parts of the human body that have an incredible plastic characteristics that allows for hope when motor function is inhibited or seemingly destroyed. Stories of regained ability to walk, talk, and function properly from stroke victims should serve as hope and a testament to the wonders of the brain.

Glossary of Terms

Axonal regeneration: compensation action of the brain after a stroke to send axons to and from the spinal cord to the effective area in the brain.
Plasticity: refers to the ability for the brain to change to utilize different pathways in a systematic manner over time
Forced limb therapy: moving a weak or unable of moving body part repeatedly to prompt stimulation and rehabilitation on the cortical and spinal level.
Descending Pathways: neurological pathways associated with the planning and execution of movement
Stroke: when there’s a sudden blood vessel burst or blood supply to the brain is inhibited-both causing a brain bleed

Localization: structure and function of the brain is rigid and unchanging. Does not allow for plasticity theory. One part of the brain can only be for one specific function. This is no longer firmly held in the neuroscience community.

Additional Anatomy/Therapy Figures

There are countless interventions that can be implemented for motor inhibited stroke patients the important thing to note that while all of these options are promising many of them are still fairly new and further advancements are surely to come.

Fig 13.
Fig 13.
Fig. 14
Fig. 14

Fig. 15

Fig. 16
Fig. 16


True and False
1. Unilateral lesions due to a stroke may cause ipsilateral motor dysfunction (T/F)
2. There are 3 types of strokes that occur from blood restriction, clots and over saturation of blood (T/F)
3. Axonal regeneration can be a natural way the brain and spinal cord attempts to compensation after a stroke (T/F)
4. Based on the location of a stroke, a doctor may be able to predict certain motor impairments a patient is suffering T/F)
5. Dendritic lengthening is not evidence to support brain plasticity (T/F)
6. Gaining full motor ability is not possible after a stroke (T/F)

Short Answer
7. What are technological advances that aid in motor rehabilitation after a stroke?
8. What happens during a hemorrhagic stroke?
9. Do strokes only effect descending pathways?
10. The Brain is ___. Why?
11. Axons in MLF innervate the motor neurons that control the axial muscles and others such as external ocular muscles. What dies MLF stand for and where does the vestibular nuclei innervate to have vestibulospinal and vestibule-ocular projections?
Neuroscience is….
a) incredible
b) exciting
c) inspiring
d) N/A

Suggested Readings

The New Jersey Comprehensive Stroke Center At University Hospital offers a great overview of the brain-breaking it down intro the cerebrum, cerebellum, and brain stem in such a way to relate information about strokes effectively and in an understandable way. Visit their website for further information or any clarification:

Any book that was written by Oliver Sacks on the brain and neuroplasticity would benefit you tremendously. I recommend reading the Anthropologist in Mars-which touched upon specifically on this topic. Sacks writes in such a way that brings theories and distant research close to home with personal stories of victory and failure of people trying to make due with often what they have been dealt after an accident of sort or sickness.

Dr. Norman Doidge is a brilliant author, researcher, and doctor and he does not disappoint in The Brain's way of Healing. This was released this year-2015, by Doidge and follows the similar pattern of The Brain that Changes Itself-which I do refer to, but brings fresh new stories, discovers and excitement to the field of brain plasticity.

New York-Presbyterian Hospital is one of the USA's most premier hospitals and they have been implementing a variety of ways to treat and help their stroke patient rehabilitate. With use of robots, mental practice and also acupuncture, these top professionals are changing how people think about recovery after stroke. Read about more of their work here:

Brigham and Women's Hospital is a distinct leader in stroke treatment and Dr. Ali Aziz-Sultan, who is the Chief of Vascular/Endovascular Neurosugery in the Department of Neurosurgery present a comprehensive video describing what a stroke is, the two types, how they as a hospital respond and treatment plans and options that are innovate and effective.

Answers to Quiz Questions
  1. 1. T
    2. F
    3. T
    4. T
    5. F
    6. Brain mapping and neuroimaging instruments, brain stimulation, neuroatomical tracers, and pharmaceutical manipulation via injections.
    7. Hemorrhagic stroke-when blood vessels suddenly burst in the brain Posterior
    8. No, the ascending pathways are changed as often times input to a damaged area of the brain is “lost” and new/other neuron have to be “
    trained” or taught how to interpret the information, i.e. sensory input going to an area from its original destination was been damaged or destroyed.
    10. Plastic. Answer on “Why” may vary but refer back to this “Brain is Plastic” to double check your work.
    11. MLF- medial longitudinal fasciculus and the vestibular nuclei innervates in the flocculonodular lobe

I hope someone finds this page to be at least a tad bit helpful.
Thank you.


[1]. Cerebellum (Section 3, Chapter 5) Neuroscience Online: An Electronic Textbook for the Neurosciences | Department of Neurobiology and Anatomy - The University of Texas Medical School at Houston. Retrieved December 1, 2015.

[2]. Doidge, N. (2007). The brain that changes itself: Stories of personal triumph from the frontiers of brain science. New York, New York: Penguin Book

[3]. Harel, N., & Strittmatter, S. (n.d.). Can regenerating axons recapitulate developmental guidance during recovery from spinal cord injury? Nature Reviews Neuroscience Nat Rev Neurosci, 603-616. Retrieved December 17, 2015, from

[4]. Johansson, B. (2000). Brain Plasticity and Stroke Rehabilitation : The Willis Lecture. Stroke, 223-230.

[5]. Kenny, D. (n.d.). Stroke | Health | Patient (D. Tidy, Ed.). Retrieved December 22, 2015, from

[6]. Pekna, M., Pekny, M., & Nilsson, M. (2012). Modulation of Neural Plasticity as a Basis for Stroke Rehabilitation. Stroke, 2819-2828.

[7]. Qu, H., Zhao, M., Zhao, S., Xiao, T., Tang, X., Zhou, D., . . . Zhao, C. (2014). Forced limb-use enhances brain plasticity through the cAMP/PKA/CREB signal transduction pathway after stroke in adult rats. Restorative Neurology and Neuroscience, 32(5), 597-609.yy

[8]. Snell, S. Richard. Clinical Neuronanatomy 6th edition. The Cerebellum and its Connections. P219-241

[9]. Stroke Induced Brain Injury. (n.d.). Retrieved December 21, 2015, from

[10]. T Belton, R A McCrea. 2000 Role of the cerebellar flocculus region in cancellation of the VOR during passive whole body rotation

[11]. Ward, N. (n.d.). Mechanisms underlying recovery of motor function after stroke. Postgraduate Medical Journal, 510-514. Retrieved December 20, 2015, from

[12]. Motor system: Basal ganglia and cerebellum - N-neurology - Medquarterly. (2014). Retrieved December 22, 2015, from

Image References

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