Introduction 

Agraphia is the loss of ability or difficulty in performing writing tasks. The two types of agraphia are Central Agraphia and Peripheral Agraphia. We often consider writing to be a straightforward and effortless task, taking this ability for granted. However, the act of writing involves a significantly more intricate process. 

Humans engage in writing by first learning graphemes, whereas in English for example, graphemes are simply the alphabet. Then, having the ability to allocate letters to produce words and sophisticated sentences. Lesions arise to disrupt this process to cause Central Agraphia. The writing process then involves the motor cortex to execute coordinate movements synched with the specific letters and write them out on a surface. The impairment to this mechanism causes Peripheral Agraphia.¹ 

Writing is extremely important in our everyday lives, we perform it more than one realises for regular mundane tasks including text messages, grocery lists and writing academic articles. The ability to write provides benefits, one being able to improve an individual’s mental health. James Pennebaker, a cognitive psychologist from the University of Texas-Austin performed research on the benefits of writing, specifically its ability to heal emotional wounds.²

His studies suggest that short-term, focused writing exercises can provide significant benefits to a wide range of individuals, including those coping with terminal illness, victims of violent crime, and new college students adjusting to the transition from high school. Evidently, writing offers benefits that are often overlooked.

One type of condition that leads to Agraphia is neurological disease. Neurological diseases refer to conditions that impact the brain, the nerves dispersed throughout the body, and the spinal cord. This article specifically will discuss the effects of two forms of neurological diseases: Alzheimer’s and Parkinson’s disease.

Alzheimer's disease and agraphia

Alzheimer’s disease is an irreversible neurological disease where neurons become deceased, causing destruction in memory and later on, the ability to perform simple tasks. Patients with Alzheimer’s possess amyloid plaques that accumulate in the space between neurons as well as a protein called tau. It generates neurofibrillary, a group of twisted fibres located inside neurons.³  The death of neurons in the human brain produces the following effects:

Memory loss 

• Struggles with recalling recent events 
• Gradual deterioration of memory capabilities 
• Increased reliance on reminders for daily tasks 
• Difficulty recognising familiar faces and places

Language impairment⁴

• Difficulty in retrieving appropriate words 
• Challenges with both verbal and written communication 
• Frequent pauses in speech as individuals search for words 
• Simplified vocabulary and sentence structures 

Agraphia is a consequence of Alzheimer’s disease. This occurs due to damages in the following areas:

1. Parietal Lobe
   • Responsible for sensory information 
   • Impairment causes difficulty in the formation of letters 
2. Temporal Lobe
   • Responsible for language comprehension and production
   • Disrupt the mental processes required for word retrieval
3. Frontal Lobe
   • Responsible for planning and executing movements
   • This affects the ability to perform the coordinated hand movements required for writing

Depending on the symptoms of the patients, different stages arise in relation to Alzheimer’s disease. The speed at which it progresses depends on factors such as the age of the patient, where any patient of age above 65 progresses more slowly in comparison to a younger individual.⁵

1. Early stage: In the early stages of Alzheimer’s, patients may experience minor spelling errors, reduced complexity in their writing and word-finding difficulties. These issues may not be immediately apparent but can be detected through detailed neuropsychological testing⁶
2. Intermediate stage: As Alzheimer’s disease progresses, patients may struggle with more pronounced grammatical errors, sentence construction and maintaining coherence in their writing. They may begin to omit words, use incorrect verb tenses and write in complete sentences⁷
3. Advanced stage: In the advanced stages, writing ability can deteriorate significantly. Patients may be unable to form coherent sentences, lose the ability to write legibly or even forget how to write entirely. At this stage, communication may rely more on verbal methods between one and the other

The manifestation of Agraphia in Alzheimer's patients can be seen through a few indicators. Other than the ones described above, it can also be indicated through overall communication challenges, where patients might avoid written communication altogether due to the difficulty in writing. As a result, this can lead to frustration and anxiety, further impacting the patient's willingness and ability to engage in written tasks.

Parkinson's disease and agraphia

Parkinson’s disease is another neurological disease that can cause uncontrollable movements due to disruption of neurons. It manifests when nerve cells in the basal ganglia are affected. This occurs due to a decreased level of dopamine as the neuron's function releases a form of neurotransmitter called dopamine. 

Moreover, patients diagnosed with Parkinson’s disease lack nerve endings which produce norepinephrine, a chemical messenger needed to control the functions of the body. They also contain α-Synuclein, a neuronal protein that disrupts cellular homeostasis.⁸ Current technologies such as Neurodiag can use the aid of software-based medical devices to help diagnose Parkinson’s Disease based on the user’s handwriting patterns. This results in the following symptoms:

• Bradykinesia (slowness of  movement)
• Tremors in legs, hands, head or jaw
• Emotional changes such as depression 
• Skin problems 
• Difficulty in reading, writing, or speaking 

Parkinson's disease can result in Micrographia, which is defined as a reduction in the size of writing letters. They can be separated into two cases: consistent micrographia and progressive micrographia. While consistent micrographia is caused by the dysfunction of basal circuits, progressive micrographia is a result of disconnections between the anterior supplementary motor area and the cerebellum.⁹ 

Comparative analysis

It is vital to understand the similarities and differences between Alzheimer’s and Parkinson’s disease to identify the effects of each diagnosis. 

Similarities 

• Both Alzheimer's disease and Parkinson's disease can lead to cognitive impairments that affect an individual's language and writing abilities. Patients may experience difficulties with word retrieval, sentence formulation, and the mechanical aspects of writing
• The writing difficulties associated with both Alzheimer's disease and Parkinson's disease tend to be progressive in nature, worsening over time

Differences 

• A clinical study conducted by Enrique Noe suggests that patients with Parkinson’s disease have better memory retainment and worse attention span in comparison to Alzheimer’s patients
• In Alzheimer's disease, the primary cause of agraphia is cognitive impairments, such as difficulties with language, memory, and executive function
• In Parkinson's disease, the agraphia is more closely linked to the motor deficits, such as tremors, rigidity, and bradykinesia 

Therapeutic interventions and management

For individuals experiencing agraphia due to Alzheimer's or Parkinson's disease, speech and language therapy can be beneficial. The focus of this therapy is on enhancing the patient's language, communication, and writing abilities.¹⁰

For individuals with Parkinson's disease who experience agraphia, occupational therapy can be helpful in addressing the underlying motor control challenges that contribute to their writing difficulties. This involves improving their fine motor skills, which are essential for the dexterity and precision required for writing. Moreover, this allows enhancement of their hand-eye coordination, helping them better control the movements of their hands and fingers while writing.¹¹ 

Furthermore, companies such as DXC Technology are developing an AI-powered algorithm to power the data point analysis to provide improved data insights that can support clinicians in their understanding of the causal factors and treatment options for individual patients.

FAQs 

Q - How common is alzheimer’s and parkinson’s disease?

A - Currently, there are 153,000 people  living with Parkinson’s disease in the UK whereas there are more than 944,000 people living with Alzheimer’s disease.

Q - When should I go see a doctor?

A - If someone is experiencing noticeable changes in their writing and language abilities, such as difficulty finding the right words or maintaining legible handwriting, this could be a sign of suspected Alzheimer's disease. Additionally, if they are also facing challenges with other cognitive functions like memory, problem-solving, or spatial awareness that start to interfere with their daily activities, and these changes gradually progress over time, it would be advisable for them to seek medical attention. 

Similarly, for suspected Parkinson's disease, noticeable changes in handwriting, like smaller and more cramped writing or increased tremors in the hands while writing, can be an indicator. Difficulties with fine motor skills and physical dexterity that affect the ability to write smoothly and legibly, along with other Parkinson's-related symptoms such as tremors, slow movements, or stiffness that start to impact daily tasks and activities, should also prompt a visit to a healthcare professional. 

In both cases, it is crucial to seek medical attention as soon as these types of changes are observed, even if they seem mild at first. Early diagnosis and intervention can be critical for managing the symptoms and potentially slowing the progression of these neurodegenerative diseases.

Q - What age does alzheimer’s and parkinson’s affect?

A - Alzheimer's is most commonly diagnosed in people over the age of 65. However, early-onset Alzheimer's can occur in people as young as 30-60 years old. The chance of being diagnosed with Alzheimer’s also increases by 10% at the age of 65. For Parkinson’s disease, the average patient is 60 where early onset can occur between 21-50.⁷ 

Summary

Alzheimer's disease

• Amyloid plaque crumbles together and protein tau tangles together to cause deceased neurons
• Disrupts memory and cognitive abilities
• Causes problems with spelling, sentence structure and, thought organisation on paper
• Handwriting may become illegible as the disease progresses  

Parkinson's disease

• Symptoms are tremors and poor coordination 
• Handwriting may become smaller and harder to read 
• Cognitive changes can also affect language 

General impact on writing

• Linguistic agraphia - difficulty with spelling, grammar, and language 
• Motor agraphia - problems with the physical act of writing 
• Spatial agraphia - issues with organising and structuring written work 

Writing difficulties often emerge as an early sign of these neurodegenerative diseases. This ultimately affects a person's written communication abilities.