Symptoms and Physical Changes in HPHA
At a Glance
HPHA combines Parkinson-like movement symptoms—usually slowness and stiffness on one side—with smaller size or structural asymmetry on that same side. Tremor, weakness, clumsiness, dystonia, and balance problems may also occur, and symptoms can remain one-sided for years.
Hemiparkinsonism-Hemiatrophy Syndrome (HPHA) is characterized by a unique combination of physical changes that affect one side of the body. While it shares some symptoms with typical Parkinson’s disease, its presentation involves more than just movement slowness. The hallmark of the condition is the presence of parkinsonism (movement symptoms) on the same side of the body that shows hemiatrophy (smaller size, bone asymmetry, or muscle wasting) [1][2].
Because this syndrome is heterogeneous, your symptoms may look different from another person’s. For instance, some individuals have clear size differences that are visible to the naked eye, while others may only show “atrophy” on a brain scan without obvious changes in their physical appearance [3][4].
The “Hemi-Parkinson” Symptoms
The movement-related symptoms of HPHA are almost always confined to one side of the body at the start, and they often stay on that side for a much longer time than in typical Parkinson’s disease, though progression can occur [5][4]. These symptoms typically include:
- Bradykinesia (Slowness of Movement): You may notice a lack of spontaneous movement, such as a reduced arm swing when walking or a mask-like facial expression [2]. Simple tasks like buttoning a shirt or using a computer mouse can become frustratingly slow.
- Rigidity: This is a specific type of muscle stiffness where your limbs feel heavy or “lead-like” when moved by someone else [2]. This stiffness can cause discomfort or a deep aching sensation in the affected shoulder or hip.
- Tremor: While not present in everyone, some patients experience a resting tremor—a rhythmic shaking that occurs when the hand or leg is relaxed but often stops when you start a task [4].
Understanding Hemiatrophy (Physical Asymmetry)
The term hemiatrophy refers to the smaller size of one side of the body. In HPHA, this wasting usually occurs on the same side as the movement symptoms (ipsilateral) [1][4]. This can manifest in several ways, and importantly, can reflect reduced growth of bone or soft tissue, congenital differences, or disuse, not just muscle wasting:
- Limb Differences: One arm or leg may be structurally smaller or shorter than the other [4]. You might notice that one shoe feels looser than the other, or that your watch strap needs to be tighter on one wrist.
- Distal Wasting: In some cases, the size difference is most noticeable in the “distal” parts of the body—the hands or the feet [4].
- Facial or Truncal Involvement: Although less common, the asymmetry can sometimes affect the muscles of the face or the trunk, leading to a subtle tilt or a slight difference in facial features [5].
It is important to note that the brain often shows the opposite pattern: if your right side is smaller and slower, a brain scan may show that the left side of your brain is smaller (cerebral hemiatrophy) [3][2].
Beyond the Basics: Weakness and Dystonia
Unlike typical Parkinson’s disease, where true muscle weakness is less common early on, people with HPHA often report a variety of other motor challenges:
- Weakness and Clumsiness: Patients often describe a sense of reduced strength or a lack of coordination in the affected hand or leg [2][3]. This might feel like your leg is “dragging” or your hand is “fumbling” with small objects.
- Dystonia: This involves involuntary muscle contractions that cause repetitive movements or abnormal postures [3]. A common example in HPHA is a dystonic hand posture, where the fingers may curl or the wrist may twist into an awkward position when you try to use it [3].
- Reflex Changes: Doctors may find reflex changes during an exam [2]. These findings must be interpreted in the context of your overall examination and evaluated for other causes.
How Symptoms Progress
The clinical presentation of HPHA is often observed for its stability in case reports. While typical Parkinson’s tends to spread from one side to the other over time, HPHA has been reported to remain predominantly unilateral for years or even decades in some patients [5][2]. However, this is not a universal rule; some patients do eventually experience symptoms on the other side [4]. Slowness, balance issues, and a loss of manual dexterity are common long-term challenges reported by patients [6].
Common questions in this guide
What are the main symptoms of hemiparkinsonism-hemiatrophy syndrome?
Does HPHA always affect only one side?
What does hemiatrophy mean in HPHA?
How can I tell weakness from parkinsonian slowness?
Can HPHA cause dystonia or unusual hand postures?
Why might a brain scan show changes on the opposite side?
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References
References (6)
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[Hemiparkinsonism-Hemiatrophy Syndrome with Hypoperfusion in Basal Ganglia: A Case Report].
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Sichuan da xue xue bao. Yi xue ban = Journal of Sichuan University. Medical science edition 2021; (52(3)):531-533 doi:10.12182/20210560106.
PMID: 34018377 - 3
Subcortical and brainstem hemiatrophy accompanied by iron deposition in a patient with hemiparkinsonism-hemiatrophy syndrome: a case report.
Chung SJ
BMC neurology 2021; (21(1)):51 doi:10.1186/s12883-021-02080-4.
PMID: 33535984 - 4
Neuropathologic findings in a patient with hemiparkinsonism and hemiatrophy syndrome.
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Neuropathology : official journal of the Japanese Society of Neuropathology 2024; (44(6)):432-439 doi:10.1111/neup.12994.
PMID: 38972833 - 5
Hemiparkinsonism or Hemidystonia With Hemiatrophy Syndrome: A Case Series With Follow-Up.
He C, Zhang P, Li Y, et al.
Frontiers in neuroscience 2020; (14()):64 doi:10.3389/fnins.2020.00064.
PMID: 32116511 - 6
Bidirectionality of the dentato-rubro-thalamo-cortical tract allows concurrent hypoperfusion in ipsilateral cerebellum and contralateral cerebral hemisphere: A case report.
He HC, Hsu MC, Hsu CS, et al.
Medicine 2018; (97(40)):e12590 doi:10.1097/MD.0000000000012590.
PMID: 30290625
This page describes HPHA symptoms and physical asymmetry for informational purposes only and does not constitute medical advice. A neurologist should assess one-sided movement changes, weakness, or atrophy in your specific situation.